Visual Response Essay

Visual Response Essay
In 2001, Morland et al. (2001) investigate the impact of visual dysfunction on cortical visual responses with three different studies. This studies differ
in the sense that the subjects have visual deficits that are expressed at different levels of the visual system. First, they describe the effects on the
cortical visual maps of abnormal retinal receptor distributions that are found in rod monochromacy (only possesses operating rod photoreceptors).
Subject KN, aged 56 year old has a complete absence of cone photoreceptors. KN also has a central scotoma which has been estimated to be between
10 min and 1Вє, but estimates are error prone due to nystagmus. The results show that the cortex undergoes a remapping whereby the regions that
would normally... Show more content on Helpwriting.net ...
Second, they evaluate how the information from each hemifield is represented in the human albino areas. In human albinism the principle deficits
occurs at the optic chiasm, where fibres undergo almost complete crossing unlike the normal pattern in which approximately half of the fibres project
contralateral to the eye. In order to address the aim, they presented stimuli to the right and left hemifields of an albino viewing monoculaly. Subject,
aged 55 year old, tyrosinase positive, female albino, who had best corrected acuity of 0.33 and nystagmus no greater than 3Вє in amplitude. They
found abnormal visual cortical activity in a human albino. Monocular stimulation of each hemifield resulted in activations in the hemisphere
contralateral to the stimulated eye. This is consistent with abnormal decussation at the optic chiasm in albinism. They believed that the reorganization
is a likely consequence of developmental and not genetic factors as found in the Boston pattern (Guillery, 1986). Finally, they described how visual
field defects can be documented with retinotopic mapping techniques in the case of cortical
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Endophthalmitis Vitrectomy Studies
Postoperative endopthalmitis is one of the most devastating complications of cataract surgery. Despite of the great progress in the lines of treatment of
this serious condition, the visual results are still poor and about 40% of cases sustain severe visual loss (corrected distance visual acuity of less than 20
/200).[1] The incidence of endophthalmitis after cataract surgery varies according to the surgical technique, it has ranged from 0.04% to 0.13%.[2–3]
This complication can end by evisceration as a last stage in management.[4]
Endophthalmitis Vitrectomy Study (EVS) results demonstrate that only patients in a subgroup of initial light perception–only vision or worse derive a
benefit from immediate pars plana vitrectomy (PPV).[5] Immediate ... Show more content on Helpwriting.net ...
Quantitative data was represented as mean, standard deviation, median and range. Data was analyzed using student t–test to compare means of two
groups and paired t–test compared pre and post results. Qualitative data was presented as number and percentage and compared using either Chi
square test or fisher exact test. Graphs were produced by using Excel or STATA program. P value was considered significant if it was less than 0.05.
Results
Baseline and postoperative data obtained for both groups are summarized in table I and II. The mean + standard deviation (SD) of age was 56.95 В±
15.75 and 53.69 В± 12.33 in group 1 and 2 respectively.
Visual Acuity
Snellen visual acuities were converted to a Logarithm of minimum angle of resolution (LogMAR) score for data analysis. This was performed by
taking log10 of the reciprocal of Snellen fraction. Grover et al, estimated a decimal VA of 0.0025 for counting fingers (CF), 0.002 for hand motion
(HM), 0.0016 for light perception (LP), and 0.0013 for no light perception (NLP).[12] By converting these values to logMAR score, we considered CF
equal to 2.6, HM equal to 2.7, LP equal to 2.8 and No PL equal to

New Born Infants And Visual Acuity
New born infants have poor visual acuity as opposed to adults. Visual acuity measures to what extent an individual can detect visual detail. Their lack
of visual acuity means they see the world a more ill–defined manner. Adult visual acuity is thirty times the visual acuity of a new born (Van Hof
–van
Duin & Mohn 1985). Atkinson & Bradrick (1981), supported this and found that new born infants could only detect the separation of lines if they are
30 times wider than the minimum width adults can detect. There is at least a five–fold improvement by 6 months of age in acuity, though it takes
several years for it to reach adult level, Brown & Yamamoto 1986. New born infants also have poor visual accommodation, needed to make sharp
retinal images at different distances. Although infant perception differs in terms of acuity, infant perception on size and shape constancy requires less
development. Adults understand that objects have a constant shape and size, regardless of their distance, and the angle of perception. The
developmental question lies on whether size and shape principles guide infant perception, or whether constancies are developed through experience.
This argument is one of many in exploring whether infants learn through cognitive adaptations, or whether they learn through experience and what the
environment offers them. Previous assumptions by Piaget, state that these principles were not present at birth, but developed towards the end of the
first year. This

Biological Processing System : Understanding Color And...
Biological Processing System: Understanding Color and Contrast
Introduction
While interacting with the world, human visual system is perhaps the first and foremost biological process system that directly involves in detecting
information. As Colin Ware (2013) noted in Information Visualization, "We acquire more information through vision than through all of the other
senses combined". Hence, it is crucial for information designers to understand influential factors which affect our visual system in order to optimize
information visualization for users. With visual sensory system acting as a signal detecting system, this paper intends to look at a variety of perceptual
elements of a particular case but mainly focuses on their visibility in terms of contrast and color. More specifically, the paper will be examining these
concepts as if the website is viewing by an elderly user.
The Case
The Town of Natick website (http://www.natickma.gov) is an online portal which contains information primarily for town residents, business owners,
and potential visitors. The website not only serves as a portal for information presenting, but also serves to accommodate certain actions, such as
applying for jobs, paying bills online, downloading business related forms. That being said, the website comprises of two primary goals: 1) to present
information; 2) to provide actionable directions to help complete certain tasks. The goal of this paper is to construct a case where the Natick website

A Brief Note On Common Geriatric Diagnosis Topic Essay
Student Name: Andrew Thorne
Common Geriatric Diagnosis Topic: Cataracts –Impaired sensory perception
Appropriate ActivityDescribe ActivityWhat are benefits of this activity for these patients?What patient education should you provide to the patient
about this activity?What are contraindications for patients related to this activity?
Visual acuity examSnellen eye chart exam –allows one to read a line of letters and numbers varying in sizeInforms the pt of visual acuity and how
much the cataract has affected vision
–catches visual acuity problems relatively earlyA large lens machine will be placed in front of your face. Bring current prescription lensesPatients who
are illiterate and do not know the alphabet.
Pt should have good cervical stability (requires leaning forward slightly)
Slit lamp examinationSit in chair with instrument in front. Place chin and forehead on support to keep steady. Eye drops are instilledAllows HCP to
examine your eyes, specifically eyelids, cornea, conjunctiva, sclera, and iris. A 2nd exam is performed to see the back of the eyeEye drops may be
instilled or a fine strip of paper stained with the dye will be touched to your eye allowing them to dilate for the HCP to see back of the eye. Bring
sunglasses for post procedure as pupils will be dilated. No absolute contraindications, but pt with open globe injury require extreme caution during
examination.
Children may be examined with parental assistance, reassurance, and special

Optician Research Paper
Optician Katy: Helping in enhancing eye care services
Opticians can be described as well trained eye care experts who have to go through extensive training to practise opticianry. In simple words they are
basically those people who dispense and design eye glasses, low vision devices, contact lenses and other ocular instruments. Professionals have to
qualify for a specific criterion which will certify that they are skilled enough to practise like an optician. They mostly work in places like hospitals,
laboratories, retail stores and eye care clinics. In USA a certified optician is educated in optical Science and he or she is entitled by the name
Ophthalmic Optician.
In recent time the demand for an optician has increased drastically. The main ... Show more content on Helpwriting.net ...
It also gives a confirmation that children possess the visual acuity to do other educational activities.
Regular checkups will ensure that you get the correct advice which will help in taking care of your eyes and make you aware of the current condition
of your eyes.
Eyes are very essential part of your life and you should take all the essential steps to maintain it. Regularly visiting your eye doctor will certify that
your eyes are in good condition and will detect any signs of severe disease.
The role of an optician Katy in an eye hospital In recent times most of the eye care clinics and hospitals have in house opticians. It is very
convenient for the patients as it saves them from the trouble of going somewhere else. Katy Optician is an essential part of any eye care hospital or
clinic. They take care of the important parts of the outpatient services. The duties of an optician have been expanded since its introduction in a
hospital setting. Their duties are providing frontline services in the tertiary structure of eye care services. They have become a very prominent part of
eye care services and every hospital is incorporating it in their

Reflection Paper
Growing up, my vision appeared to get worse and worse every year. Until I was in first grade I never thought to told my mom, considering it never
caused any problems. It was until I would find myself squinting at the board everyday did my teacher wonder if something was wrong. Shortly after, I
found out I needed glasses. From first grade to tenth grade, I went through multiple pairs of glasses, and my vision continued to deplete. I never
complained about having glasses because they rarely got in my way. That was until high school, when I started running. Trying to sprint with glasses
on can be extremely challenging. It took me two years to finally get the courage to get contacts. As someone who struggled with getting contacts in
everyday over the summer and struggles now, I want to help those who go through the same conflict. Waking up in the morning you are presented
with two choices, either take out the contacts that you had in last night, or you wake up blind, and have to groggily feel your way to the bathroom.
As you reach around for your contacts, you must not forget to knock over various of your toiletries in the process. Disregarding everything strewn out
on the floor, open your contact packages. Not even caring that you just spilled saline over your shirt, sink, and hands, try helplessly to grab one contact
out of the package. Personally, since I have two different prescriptions for each eye, I start with my right eye. Now you begin. Set aside five minutes of
this

PREVALENCE OF NON STRABISMIC VERGENCE DYSFUNCTIONS IN AN...
PREVALENCE OF NON STRABISMIC VERGENCE DYSFUNCTIONS IN AN ORTHOPTIC CLNIC
INTRODUCTION
In the preceding generations, fine distance visual acuity and stereoscopic vision were of paramount importance, since the survival depended absolutely
on the capability to farm, hunt and fish. But today, the emphasis has shifted virtually from distance visual functions to two dimensional near visual
tasks such as desk work, reading, computer usage etc.The presence of non strabismic binocular dysfunctions such as accommodative and vergence
anomalies make it difficult for the visual system to perform these kind of activities with accuracy and effortlessness. When persons, who are in short of
suitable accommodative and vergence amplitudes, are involved ... Show more content on Helpwriting.net ...
In a clinical study to determine the presence and clinical implications of the general binocular dysfunctions in a population of university students,
Esteban Porcar et al 4 found a prevalence of 32.3 % of non strabismic binocular anomalies.
To achieve as estimate of the population prevalence of vergence dysfunctions, we have systematically reviewed the previous studies related to this. So
this study was designed to estimate the prevalence of vergence dysfunctions in an orthoptic clinic set up and also to set up well defined diagnostic
criteria for all the vergence anomalies.
MATERIALS AND METHODS
755 Patients above the age of seven years presented consecutively to the orthoptics clinic of Sankara Nethralaya, Chennai between March 2010 and
February 2011 was considered for this retrospective cohort study based on the inclusion and the exclusion criteria with the help of Medical Record
Department and Electronic Medical Record (EMR) search engine.
The inclusion criteria used were age more than or equal to seven years, distance best corrected visual acuity of > 6/9 in both the eyes, near best
corrected visual acuity of N6 @ 30–40 cm, adequate sensory fusion with worth four dot test for distance as well as for near, Random Dot stereo
acuity of 500 arc seconds or more. All the patients who had a history of monocular or binocular amblyopia, manifest

Visual Acuity
Visual acuity is a screening procedure that is concentrated on the diagnosis of an illness and measures visual acuity. This procedure is often done by
the medical assistant in a well–light area or room. "The medical assistant should observe the patient to look for any condition or behavior that could
possibly indicate visual distance, such as tilting the head forward or to the side, excessive blinking or eyes watering, frowning or puckering the face,
closing of one's eyes when testing both of the eyes and signs of straining to see. Common devices used to measure distant vision is a Snellen chart.
This chart will show the distance an individual can read the chart from. For an individual with reading troubles a chart with letter E's arranged

The Perception Of A Infant 's Visual System
The phenomena of perception refer to the sensory processes that enables human beings to recognize and organized the information that is received
from the environment. Such process allows individuals to perceive the world and objects. For such process to occur, theorists research visual
perceptual patterns during the period of infancy. Research has found that there are differences between the way a newborn infant perceives the world in
comparison to adults, as their visual system is not fully developed at such an early age. An infant's visual system is heterochronus which disables them
from seeing a complete view of the world, compared to adults.
An individual's visual system is constructed by different components. The eye and the brain perform different functions and go through different
processes from the moment light is reflected from an object to actually obtaining visual recognition. Vision relies on the response of the nervous
system to the light that has been reflected from an object, during this process many parts of the human eye are active. When a ray of light enters the
pupil of the eye, the cornea refracts the lights and focuses the lights on the lens which focuses the light at the back of the eye in the retina. The retina
then converts the light via optic nerves which enables the information to be processed in the brain, enabling visual recognition of the image which we
see (Wade, 2001). This process is necessary, so individuals are able to comprehend what is

The, The Silent Thief, By. Levi, Knill And Bavelier
Draft essay
Amblyopia is described by; Levi, Knill and Bavelier (2015) as a neurodevelopmental disorder of the visual cortex. A disorder characterised by Rose
(1998) as the "silent thief", a term that purportedly portrays the consequences of amblyopia going undetected. Amblyopia has been reported as the most
common cause of monocular blindness worldwide Wong (2012), and in a recent review conducted by (Tailor, Bossi, Greenwood and Dahlmann
–Noor,
2016) was cited the most common visual deficit among children in the UK. Bretas and Soriano (2016) describe amblyopia as the result of visual
deprivation due to impaired binocular function. An impairment thought typical of the two most commonly proposed underlying causal factors;
strabismus and ... Show more content on Helpwriting.net ...
Importantly, findings demonstrate the potential plasticity of the adult brain beyond the hypothesised critical period for visual development, Tailor et
al., (2016), Nancy (2015). Critically, binocular treatments are producing encouraging improvements among adult amblyopes Vedamurthy, Nahum,
Bavelier and Levi (2015), Li et al., (2013), posing important implications for clinical practice. The aim of this essay is to explain amblyopia with
reference to 'strabismus and anisometropia'. To discuss traditional methods and newly developed binocular treatments that aim to address the binocular
dysfunction of the amblyopic brain.
Amblyopia occurs during the first 3 years of life Levi et al (2015) and doesn't develop beyond the age of 8yrs supporting the 'critical period' of
susceptibility. However, this doesn't evident a theory for a null treatment effect among amblyopes beyond this period.
STUDENT NUMBER 119049491
Anisometropia causes blurred vision usually in one eye inhibiting normal visual perception and thus causing disparate visual input to the cortex Tailor
et al., (2016). Clinically anismetropia is described as a difference in refraction between the two eyes Barrett (2004). Tailor et al., (2016) describes
strabismus as a misalignment of the visual axes also resulting in incongruent visual input to the visual cortex, thus both anisometropia and strabismus
cause binocular dysfunction. The

Comparing Visual Systems: Bats Vs. Humans
Leah Meltser PHBM 207.01 Assignment 1: Comparing Visual Systems 2/12/17 Visual Systems: Bats Versus Humans One has probably heard the
simile, "you must be blind as a bat!" Well in fact, this statement is false, bats are not blind. Formally known in the mammal family as Chiroptera, bats
can be split into two sub orders known as mega–bats (flying foxes or fruit bats) and micro–bats. Typically, when bats are thought of it is commonly
known to have the characteristics of having echolocation, or sonar vision, to aid detection of objects in complete darkness. As illustrated in Figure 1,
echolocation is the use of sound waves made by the contraction of the larynx, these waves are then reflected back from the moving object to signal the
bat.... Show more content on Helpwriting.net ...
Both bats and humans have a threshold of approximately 10–7 Apostilbs, which is a measurement of light density. However, a flying foxes' acuity is
maintained much longer as illumination decreases until roughly 10–4 Apostilbs, which is when acuity begins to fall off as demonstrated by the Figure
3. Likewise, both humans and flying foxes have similar positioned eyes toward the front of the skull providing binocular vision. This means that
both eyes are being used at the same time in order to create a greater depth of field. Both visual systems contain a majority of the same structures,
but overall, they are completely different systems due to the fact that we are not nocturnal, nor do we need to be. Although the visual systems of bats
and humans vary in many ways, both visual systems have evolved to benefit each species differently. While humans see life in color with their cones
during the day, bats are the kings of nocturnal mammals and are capable of maneuvering throughout the night. It has become clear that bats are
capable of so much more then just echolocation from a visual perspective. It is beyond fascinating to realize that what was once thought of as true, is
actually false in reality. Therefore, it is safe to say that the phrase "you are as blind as a bat," can be put to

How Vision Loss Affects Psychosocial Well Being Among The...
Abstract Purpose: to examine how vision loss affects psychosocial well being among the people in the middle and upper class and how the cope with
their visual impairment
The purpose of this study is to understand and discover the psychosocial state and well–being for individuals with vision loss among the upper and
middle class. At this stage in the research, the participants chosen will be asked about their mental state and vision loss, which will be generally
observed through interview questions on PTSD, depression and motivation. Previous studies have stated that overall poorer mental well–being and
quality of life was found in visually impaired people in comparison to fully sighted people (Stevelink & Fear 2016).
Method: Qualitative study, interview research questions
Keywords: Visual Impairment, Vision loss, Psychosocial well–being, PTSD, depression, motivation
_____________________________________________________________________________________
Introduction
Visual impairment is a state wherein an individual experiences difficulty in seeing or not being able to see anything physical presented to them.
According to Mandal, MD (2013) It is a state where a visually impaired person's eyesight cannot be corrected back to a "normal level". Visual
impairment is often associated with old age. In Europe, an estimated 15.5 million people have visual impairment and in seven countries in Europe,
about 50% of blindness is caused by age–related macular degeneration. (Dibb,

Cataract Surgery
Definition
A cataract is defined as an opacity of the lens of the eye that causes partial or total blindness. The word is derived from the Latin "cataracta", which
means "waterfall." To the eye of an observer, the foamy white opacity of an advanced cataract resembles that of the turbulent water of a waterfall.
(Chang, Cataracts Definition, 2014)
Etiology
The lens is a naturally clear, transparent, and avascular structure located behind the iris. Light passes through the transparent lens to the retina to
produce clear, sharp images on the retina. The lens is made mostly of water and protein fibers. The protein fibers are arranged in a precise manner that
makes the lens clear and transparent. When the lens undergoes changes, and the structure ... Show more content on Helpwriting.net ...
Studies show that overall 89.7% of post–surgery cataract patients achieved 20/40 visual acuity or better. To put into perspective, visual acuity of 20/40
is the acuity necessary to obtain an unrestricted driver's license (Powe, Schein, Gieser, Tielsch, Luthra, Javitt & Steinberg, 1994).
Patients can resume normal activity such as reading, walking, eating, and watching television the evening of surgery.The eye may be patched,
depending upon whether anesthesia was local or topical. The eye is typically examined on the first post–operative day. Many surgeons allow
resumption of driving at the level immediately prior to surgery at this time, as long as continued patching is not required. Sutures are removed at 6 to
12 weeks if there is suture–induced astigmatism. (Jacobs, 2015)
Patients typically are seen one day, one week, and one month after surgery to monitor for complications and proper healing. Patients with large
incisions typically are advised not to undertake heavy lifting or strenuous activity for several weeks to several months. Patients with smaller incisions
could resume regular activity after a period of days to weeks. (Jacobs,

Visual Acuity Lab Report
Results
Demographics
Were included 82 eyes of 49 patients, 32 (69%) females and 17 (31%) males. The mean patient age was 33 +/– 7.4 years (range: 21 to 48 years). Mean
follow up was 4.8 years (range 9 to 1 year). The mean anterior chamber depth was 3.2mm (range 2.8 to 3.67mm). Were implanted 42 Artisan IOL and
40 Artiflex IOL with a mean power of–11.1D
Visual Acuity
Mean preoperative UCVA was 1.9 logMAR and post operative UCVA was 0.3 logMAR after phakic IOL implantation, showing astatistical significance
(p=0.000).
After the surgery we observed that 79 eyes gain 4 or more lines of vision, 20/40 or better was achieved in 76 eyes (92.68%) after the follow up period.
Mean preoperative CDVA was 0.2+/–0.3 logMAR and after post operative follow up period was 0.01+/–0.1 logMAR, which was statistically ... Show
more content on Helpwriting.net ...
Postoperative central endothelial cell count after the follow up period was 2323+/–286.03 cells/mm2, which was observed a statistically significative
decrease in the cells count. The mean ECD yearly lost was 121.36 +/–111.04 cells/mm2/year.
IOL distance from Endothelium
Mean distance from the center of the pIOL to the endothelium was 2.2 +/– 0.3mm and the mean distance from the edge of the pIOL was 1.4 +/–0.2mm
both distances were lowly correlated to the endothelium cells loss (r–0.00 p0.000 and r –.308 p0.05 respectively)
Intraoperative Problems and Adverse Events
There were no intraoperative or postoperative problems. However in one patient elevated intraocular pressure (IOP) were detected at the postoperative
control. Were considered steroid induced, the IOP returned to baseline levels after cessation of steroid. Throughout all follow–up years, a total of 5 eyes
of 5 patients have been received a new intervention due to a tilt of the lens or had been dislocated from the iris. In this patients the endothelial cells
loss was much higher than the

Assignment 1: Explain The Concept Of Exam Lane
Goal: Explain the concept of "exam lanes" and rank on Google for the key phrase
Total words in this document:
Title: Excellent Exam Lanes: What You Need to Know
Exam Lanes 101: A Crash Course
More than just an exam room, an exam lane is the comprehensive site where patients have their vision checked and ophthalmic professionals spend
eight to ten hours of their day conducting exams and meeting with patients.
Exam lanes include a number of pieces and tools to diagnose various conditions, prescribe corrective lenses for patients, and give detailed, descriptive
reports that improve the ease of diagnosis while reducing the margin of error. These pieces range from the seat where patients sit for the exam to the
slit lamp, visual acuity system, and more in–depth pieces designed to measure and test parts of the eye.
In the past, exam rooms were the ... Show more content on Helpwriting.net ...
Creating an efficient exam lane, first and foremost, is vital to providing professionals with a workstation that is conducive to good health for the
professional as well as the patient. Rather than hunching over a slit lamp, stretching to reach an ophthalmoscope or visual acuity tool, or contorting
your body to fit the demands of using a manual refractor, newer exam lanes include automated equipment that alleviates pain. The exam chair and slit
lamp are set to an optimal height that helps to reduce the risk of severe discomfort and later physical conditions.
Compact: An efficient exam lane will have space for each necessary component. By purchasing a package, the exam lane has been designed to
provide a space for each tool. Not only will this increase the ergonomic benefits, but will also save time during each appointment. Rather that searching
for tools when they are needed, the exam lane will allow professionals to find what they need, when the item is

Amblyopia Essay examples
Amblyopia
This paper provides a brief description of amblyopia and discusses current research regarding the motion pathway in individuals with amblyopia.
Amblyopia is a condition in which visual acuity in one eye is greatly reduced. It is caused by lack of stimulation or disuse during visual development
(Rose, 1998). Because the eye is not fully developed at birth (Jarvis, 1992, as cited in Rose, 1998), infants need stimulation to complete the visual neural
pathway. When one or both eyes are inhibited, for example due to misalignment of one eye (strabismus) or a large difference in refractive power
between two eyes (anisometropia), the neural pathway for the inhibited eye develops abnormally, or does not develop at all. At... Show more content on
Helpwriting.net ...
This information is important because it could provide meaningful insight into the nature of the underlying problems involved (Hess & Anderson, 1993).
There is a general consensus that amblyopes have reduced contrast sensitivity, grating acuity, and spatial resolution in one eye and a loss of
binocular vision (Levi, 1991; Sireteanu et al., 1977, as cited in Fahle & Bachmann, 1996). Amblyopes also suffer from "crowding" (Levi & Klein,
1985, as cited in Fahle & Bachmann, 1996) which causes difficulty, for example, in comprehending a letter found in text rather than an isolated letter.
The mechanisms delegating positional information are also disabled in amblyopes (Rentschler & Hilz, 1985, as cited in Fahle & Bachmann, 1996).
Even though amblyopia results in a profusion of visual obstacles, there is one area for which amblyopia may actually provide beneficial. Arguments
have been made that while fine spatial detail has been affected in amblyopes, the motion pathway has not been affected (Chung & Levi, 1997;
Kubova, Kuba, Juran, & Blakemore, 1996), and may even be more acute (Fahle & Bachmann, 1996). It has been proposed that in amblyopes the
parvocellular pathway is impaired resulting in loss of fine spatial detail (Kubova, et al., 1996). On the other hand, parasol cells that lie in the
magnocellular layers

Cortical Visual Impairment
Some of the issues that plague individuals with cortical visual impairment are losses within central and/or peripheral vision, inability to perceive depth,
sensitivity to light, color or contrast and frustration. Research by Roman, Baker–Nobles, Dutton, Luiselli, Flener, Jan, Lantzy, Matsuba, Mayer,
Newcomb, & Nielson states that 'CVI should be defined, albeit arbitrarily, by a reduction in visual acuity, in the visual fields, or in a child's ability to
see compared to other children of the same age." (Roman, Baker–Nobles, Dutton, Luiselli, Flener, Jan, Lantzy, Matsuba, Mayer, Newcomb, & Nielson,
2010) When an individual has CVI they usually rely more on their peripheral vision than their central vision. Most of the items we see require some

Cataract: Currable Blindness In The World
Cataract is the most common cause of curable blindВ¬ness in the world. It remains the leading cause of blindness in India (62.60%) (Vijaya L et al
2005 ). High quality, high volume cataract surgery is needed in community eye care centres to effectively manage the large back–log of cataract
blindness (Natchiar G et al 1994 ). The number of cataract extraction procedures performed all over the world is predicted to increase under the
auspices of Vision 2020 Global Initiative about 35 millions by 2020 (Taylor, 1999 ). Couching is the first surgical procedure known to treat cataract
surgically and is only of historic interest. Intracapsular cataract extraction (ICCE) is now obsolete. Cataract extraction with intraocular lens
implantation is widely

Accommodations Project
The disability group that I would like to focus on for my Accommodations Project is blindness and low vision. According to the textbook, "the
statutory definition of blindness is based on visual acuity and field of vision. Visual acuity is the ability to clearly distinguish forms or
discriminate details at a specified distance" (Heward 345). For example, Mary is able to see the words on the projection screen from her desk and
she can see it clearly. Having 20/20 vision does not mean that a person has perfect vision it simply means that they can see at a distance of 20 feet.
The American Foundation for the Blind defines being legally blind as having vision "no better than 20/200 corrected vision in the better eye, or a
visual field not extending beyond 20 degrees in the better eye, or a visual efficiency of no more than 20 percent. The "legal" refers to a... Show more
content on Helpwriting.net ...
There are many instructional strategies that are effective in teaching students who are blind or that have low vision. One example of an instructional
strategy would be seating the student in the front of the classroom so that they can hear the teacher's instructions clearly (Allan). A student that is
blind is unable to see written instructions that are on a chalkboard so the teacher will have to read the instructions aloud. Another example "would be
to avoid leaving doors and drawers ajar or chairs out from under tables and desks" (Allan). If there are items in the walkway of a student that is blind
they could potentially fall and get hurt which is why it is also important for the teacher to keep from rearranging the classroom. If the teacher rearranges
the classroom they should inform the student that they have done so. The two examples that I provided are effective because they help the student be
successful in the classroom despite their

Description Of The Barn Owls Essay
Outline I.Introduction II.Barn Owls a.The Barn Owl is an extremely specialized nocturnal marauder with exceptional preying skills. b.They are also
notorious for their advanced sound–localization capabilities. c.The visual system in the Barn Owl shows anatomical, purposeful, and physiological
specializations. d.Front Facing Eyes with high–quality optics which create an abnormally large binocular field of observation which is a sign for
increased ethological importance for the use of stereo vision e.Barn Owls have coupled modification in both eyes and an enlarged Wulst. i.With this
comes a high level of binocular interaction and selectivity for binocular inconsistency. f.Owls have global stereopsis and use disparity, the
inconsistency, as a depth cue with hyperacute exactness. g.Barn Owls are able to make out illusionary contours. h.Owls have very limited potential in
moving its eyes relative to its head. i.The eyes nor the ears move separately from the head in owls. i.The image quality in the eyes of the Barn Owl is
exceptional. j.III.Vernier Acuity a.Vernier acuity is the capability to identify tiny spatial offsets in paired lines, dots, or objects. b.Currently, humans
can determine the relative positional alteration of spatially non–aligned features with meticulousness that corresponds to a small percentage of the eye's
resolving power. c.Does the Barn Owl display hyperacuity in a Vernier task? i.In the experiment, a simple one–up and one–down

Safely Inserting Contact Lens
Safely Inserting and Removing a Contact
Inserting a contact lens. A skill I never thought I would need until the day arrived for an annual doctor's appointment and my doctor told me I should
go see an ophthalmologist (an eye doctor). Needless to say, after a visit with the burly eye doctor, I had gotten glasses and was still refusing to get
contacts. I knew I probably needed them, but the thought of sticking my finger in my eye to but in a rubbery circular thing gave me the chills. It just
wasn't natural. And I went a long time with just my black rimmed glasses, that is, until soccer season came around. I was fine. I could see... couldn't I?
That was what I asked myself after been hit in the face with the ball during my team's first game. Was ... Show more content on Helpwriting.net ...
Took you long enough. But now, what about safety? You're probably saying "Safety? I'm not riding a bike." It might be a lot smaller than a bicycle,
but it's no less dangerous. An unsanitary contact can cause bacteria to grow in your eye resulting in certain funguses to grow which can ultimately
cause blindness. Even going to the beach with contacts can be bad. Sand particles can get under your contact and scratch at your eye without you even
noticing until it's too late and your eye is damaged, sometimes beyond repair. Even sleeping in your cantact are a big no

Overall Characteristics Of Selected Trials And Quality...
Results Overall Characteristics of Selected Trials and Quality Assessment A total of 1736 articles were initially identified. Of these, 1687 were
excluded according to the exclusion criteria listed above. The 49 remaining articles with full texts that met the inclusion criteria were assessed.11, 14,
17–19, 25 A total of 4 studies were included in this review. One study compared aflibercept with bevacizumab and ranibizumab for centre–involved
DMO using a standardized follow–up and retreatment regimen.17, 18 Due to there being only one study comparing aflibercept with other anti–VEGF
agents, it was not included in the meta–analysis. Figure 1 provides a flow diagram of the search process. In total, there were 661 patients included in
this meta–analysis: 331 patients in the aflibercept group and 330 patients in the photocoagulation group. The characteristics of the studies included and
risk of bias assessment are summarized in Tables 1 and 2. The DA VINCI study compared photocoagulation with monthly, bimonthly and as needed or
pro re nata (PRN) intravitreous aflibercept regimens. The PRN regimen was selected for data extraction because this is the current practice with other
anti–VEGF drugs. The VISTA and VIVID studies compared photocoagulation with 4–weekly intravitreous aflibercept (2q4) and a regimen of five
initial 4–weekly intravitreous aflibercept followed by 8–weekly injections (2q8). The 2q8 regimen was selected for data extraction as the total number
of injections in

What Is A Cataract?
A cataract is a condition in which the transparent lens becomes progressively opaque due to varying circumstances such as genetics, environment, and
diet, amongst many other variables. Regardless of the pathogenesis from which the cataract developed, a reduction in visual performance and thus,
visual acuity is exhibited. In order for the visual acuities to be enhanced again, the cataract needs to be removed. An ophthalmologist will remove it and
replace the natural lens with an intraocular lens (IOL). Cataract surgery has shown to be one of the safest and most effective type of surgery in which
patients report having better vision in a matter of a few days. Briefly, cataracts are cloudy areas that form in the lens that make it difficult ... Show more
content on Helpwriting.net ...
Retinal illuminance is a key factor in the sharpness of someone's vision and in turn, their visual acuities. If not enough light is reaching the retina, the
human brain cannot distinguish between certain details in a word, much less a letter. The cataract, depending on where it is located in the lens, causes
light to bend around it in an effort to reach the retina with full illuminance. This allows the light to reach the photoreceptors of the retina, which can
then be transduced into a chemical signal that follows its pathway to eventually, the visual cortex. This results in an image perceived by the brain.
However, if the cataract is big enough, it can prevent the light from reaching the photoreceptors and disrupting the whole process of the visual system.
Therefore, it is imperative that the lens be free of noise in an effort to transduce as much light as possible to the retina. This means removing the
cataract, thereby increasing a person's visual acuity.
In conclusion, cataracts not only affect visual acuity and contrast sensitivity, it affects the quality of life for those that have the condition. It is
important to detect, monitor, and treat cataracts if it becomes an issue in performing everyday tasks such as reading, driving, and detailed work at
near. By completely removing cataracts or replacing the lens, patients are better able to improve their visual acuities and perform such tasks.
Removing cataracts at an earlier age can also have long lasting effects on visual performance and quality of life in their

Cortical Visual Impairment
HISTORY: For early diagnosis of disorders presenting marked cortical visual impairment, VEPs were considered crucial diagnostic test since advent of
EEG and multiple variants to this protocol have come into existence as described below.
a.FLASH VISUAL EVOKED POTENTIAL:
Adrian et al (1934) proved that the regular repeating flash stimulus could induce the electric response from the visual cortex. E. Herba et al (2006)
employed FVEPs to show that the maternal zinc supplementation may have a beneficial influence on visual cortical responses in newborn rats.
FVEPs have been regarded as the consequence of increased excitability of cortical circuitry to flash stimulation (FVEP) (Aguglia et al., 1991; deSeze
et al., 1998; Finsterer et al., 1999; ... Show more content on Helpwriting.net ...
Low–speed blinking light (i.e., blinking frequency of less than 3.5 Hz) generates transient VEPs and characterized with a negative peak of around
75ms and a positive peak of around 100ms. According to waveform patterns VEPs, categorization seems appropriate as transient VEPs and SSVEPs.
The function of pattern size quantifies visual acuity through electrophysiological parameters of amplitude and latency26–31. The amplitude and
latency of the VEP have been studied in adults, children, 32–33 and term infants 34. In the preterm infants, it shows developmental kinetics of the VEP
response and the age of its stabilization34, 35–37.The lack of clinical relevance of the VEP in infants in whom ROP stages 4b and 5 developed also has
been established38–40. While transient VEPs occur in reaction to visual stimuli which blink at a frequency of less than 3.5 Hz, SSVEPs occur in
reaction to stimuli of higher blinking

Classification System ( 17 ) Essay
All patients were diagnosed with a stage 2, 3, or 4 idiopathic MH according to the Gass classification system(17) and underwent a comprehensive
ophthalmologic examination before and 1, 3, and 6 months postoperatively, including measurement of the best–corrected VA (BCVA), binocular
indirect ophthalmoscopy, and non–contact lens slit–lamp biomicroscopy. The SD–OCT examination also was performed in all patients on the same day
as the clinical examination. Standard 3–port pars plana vitrectomy for MH repair consisted of a core vitrectomy with intravitreal injection of
triamcinolone acetonide to visualize the vitreous gel, surgical creation of a posterior vitreous detachment if it had not yet occurred, ILM peeling using
Briliant blue G (BBG), and fluid–gas exchange followed by flushing with a mixed non–expansile concentration of 20% sulfur hexafluoride. Patients
were instructed to remain facedown for 2 to 7 days postoperatively. Anatomic success was defined as the presence of a flat or closed MH 1 month
postoperatively confirmed by biomicroscopy.(18) All patients provided written informed consent after they received a detailed explanation of the
surgical procedure and SD–OCT follow–up examinations. Our retina specialist (SB) performed the surgeries. One of two experienced examiners
performed the VA examinations, and experienced technicians conducted the SD
–OCT examinations. The study adhered to the tenets of the Declaration
of Helsinki and was approved by the institutional

Visual Impairment Paper
As a person with a major visual impairment myself, I found the first video fascinating. In the video the audience is introduced to Mason, a 6–year–old
boy, whom is completely blind in one eye and has only partial vision in the other. His overall visual acuity is approximately 20/300 versus the
standard visual acuity of 20/20. In the video the types of technology introduced and discussed were the Mountbatten Brailler, iPad, and a Smart
Board. A Mountbatten Brailler is a type of Braille machine, which in a traditional braille machine that has been equipped with audio as well as word
processing capabilities. It's particularly useful for children because of the audio responses. Mason also utilized an iPad at home and in school as an
additional education tool because of the capabilities to run education games and increase the size of text and images to make it ... Show more content on
Helpwriting.net ...
Cerebral Palsy is a permanent and debilitating condition that causes not only a physical impairment and disability but in cases like Elle can cause
communication disabilities or even cognitive defects. Elle is unable to speak so her main piece of assistive technology is a Dynavox, which is a
speech–generating device that is operated by a head mouse that allows Elle to communicate and express herself. Prior to acquiring the Dynavox her
family had been through multiple devices and assistive technology items. They used a traditional book chart. Which consists of a book broken into
categories of basic needs and communication symbols and the user shifts their eyes from one category to another in order to communicate. They used a
device called a Pathfinder, which is also an assistive communication device that looks like a large board with multiple buttons. They eventually began
utilizing a laptop with communication software and eventually the school helped her find the Dynavox, which gave her better communication

Diagnosis And Treatment Of Nursing Essay
A consecutive series of patients who had undergone anatomically successful MH closure and were followed for at least 6 months postoperatively were
enrolled in this study. All patients were diagnosed with a stage 2, 3, or 4 idiopathic MH according to the Gass classification system(17) and underwent
a comprehensive ophthalmologic examination before and 1, 3, and 6 months postoperatively, including measurement of the best–corrected VA (BCVA),
binocular indirect ophthalmoscopy, and non–contact lens slit–lamp biomicroscopy. The SD–OCT examination also was performed in all patients on the
same day as the clinical examination. Standard 3–port pars plana vitrectomy for MH repair consisted of a core vitrectomy with intravitreal injection of
triamcinolone acetonide to visualize the vitreous gel, surgical creation of a posterior vitreous detachment if it had not yet occurred, ILM peeling using
Briliant blue G (BBG), and fluid–gas exchange followed by flushing with a mixed non–expansile concentration of 20% sulfur hexafluoride. Patients
were instructed to remain facedown for 2 to 7 days postoperatively. Anatomic success was defined as the presence of a flat or closed MH 1 month
postoperatively confirmed by biomicroscopy.(18) All patients provided written informed consent after they received a detailed explanation of the
surgical procedure and SD–OCT follow–up examinations. Our retina specialist (SB) performed the surgeries. One of two experienced examiners
performed the VA

Period Of Susceptibility In Kittens
1.The period of susceptibility, as defined in the present study, is a critical period in which vision is developed. The researchers discovered that the
period of susceptibility in kittens has a sudden onset at the beginning of the fourth week of life. A gradual decline in the period of susceptibility is seen
sometime between the sixth and eighth weeks of life and continues through the end of the third month of life. By the end of the third month and the
beginning of the fourth month, the period of susceptibility disappears.
2.Figure 2 consists of two histograms (Figure 2A and Figure 2B) depicting the ocular dominance distribution of cells in the left visual cortex of two
kittens born of the same litter. In this part of the study, the... Show more content on Helpwriting.net ...
Figure 9 contains two ocular dominance histograms of the left visual cortexes (9A and 9B) in which two kittens had a period of monocular
deprivation in their right eyes during the first three to four months of their lives. In Figure 9A, both eyes were kept open for thirty months and
then the results were recorded, which shows ocular dominance in the left eye (expected based on the research). However, in Figure 9B, following
the original period of deprivation in the right eye, the kitten's left eye was then sutured closed for a complete year, after which remained open with
the right eye for four years and ten months. The results of this cat were recorded at age six years and one month. One may expect the results in
Figure 9B to show ocular dominance in the right eye due to the fact that the left eye was closed for a longer period of time (roughly 8 months).
However, the results instead show ocular dominance in the left eye like Figure 9A does. This can be explained based off of the research that the
period of susceptibility ends around the fourth month of life. Because the right eye was deprived during the period of susceptibility, but the left eye
deprivation occurred after the conclusion of this sensitive period of cell growth and connection formation, the left eye displayed dominance. This again
suggests that the length of deprivation does not necessarily matter as long as it does not occur during the period of

Essay on Visual Acuity as a Function of Retinal Eccentricity
Visual Acuity Measured as a Function of Retinal Eccentricity
Visual acuity is a measure of an observer's ability to see fine spatial detail (Cavonius & Schumacher, 1966). There are a number of factors that
affect visual acuity, such as illumination and contrast, and various ways to measure it (Kalloniatis & Luu, 2005). One way to measurevisual acuity
is through target detection which requires the perception of the orientation of a stimulus such as a Landolt C or a Snellen E (Kalloniatis & Luu,
2005). The participant in the current experiment was referred to have their acuity tested. Target detection of a stimulus was used to measure the
participant's visual acuity as a function of retinal eccentricity of the target. ... Show more content on Helpwriting.net ...
The height and width of this optotype is designed to be five times the thickness of the stroke width and gap width, therefore the size of each critical
detail is 1/5th of the overall height (Kalloniatis & Luu, 2005). Four stimulus sizes were used in the experiment as visual acuity was to be tested at
four eccentricities (0Лљ, 20Лљ, 40Лљ and 60Лљ). These four stimulus sizes were calculated using the approximate minimum angle of resolution
(MAR) of each eccentricity obtained from Millodot et al.'s (1975) normal data. This value was then used to find the gap size and hence the stimulus
size using a distance of 600cm. The reason for using the distance value of 600cm was because it is close to the threshold and therefore would be the
starting point of stimulus presentation for each of the eccentricities. The formula used was: gap size = 600*tan(MARЛљ) ЛѓЛѓ size = 5
(600*tan(MARЛљ))
The stimulus sizes (and critical feature sizes) calculated and used for the eccentricities 0Лљ, 20Лљ, 40Лљ and 60Лљ were 0.9cm (0.18cm), 2.2cm
(0.44cm), 6.13cm (1.23cm) and 17.5cm (3.5cm) respectively.
Procedure
As already stated, it was decided by the experimenter to test visual acuity at the following eccentricities: 0Лљ, 20Лљ, 40Лљ and 60Лљ. Measuring the
MAR at each of these eccentricities would give a good indication of where the participant's visual acuity measure lies in comparison to normal data.
Exact vertical and horizontal

Pseudo Myopi The Refractive Anomaly Of The Eye
INTRODUCTION
Myopia is the refractive anomaly of the eye in which close objects appears clearly, while objects far away appear blurry. With myopia, light comes to
focus in front of the retina instead of on the retina Myopia is the major refractive error having a worldwide prevalence of 1.5 billion. Children with
Myopia feel difficulties in viewing blackboard in school; they avoid outdoor activities and get isolated from the peer groups. Untreated myopia may
lead to Macular degeneration, Glaucoma, Cataract, Retinal detachment.
Myopia occurs if the eyeball is too long or the cornea (the clear front cover of the eye) is too curved. As a result, the light entering the eye isn't focused
correctly, and distant objects look blurred. Even though ... Show more content on Helpwriting.net ...
Because there is insufficient contrast for an adequate accommodative stimulus, the eye assumes the intermediate dark focus accommodative position
rather than focusing for infinity.
3. Pseudo myopia
Pseudo myopia is the result of an increase in ocular refractive power due to overstimulation of the eye's accommodative mechanism or ciliary spasm.
The condition is so named because the patient only appears to have myopia due to an inappropriate accommodative response.
4. Degenerative Myopia
A high degree of myopia associated with degenerative changes in the posterior segment of the eye is known as degenerative or pathological myopia.
The degenerative changes can result in abnormal visual function, such as a decrease in best corrected visual acuity or changes in visual fields. Sequelae
such as retinal detachment and glaucoma are relatively common.
5. Induced Myopia
Induced or acquired myopia is the result of exposure to various pharmaceutical agents, variation in blood sugar levels, nuclear sclerosis of the
crystalline lens, or other anomalous conditions. This myopia is often temporary and

Clinical Procedures For Ocular Evaluation
Clinical optometrists take on the task of routinely evaluating and dealing with patients on a daily basis while also attempting to maintain a healthy,
successful business environment. The book Clinical Procedures for Ocular Evaluation describes how clinical optometrists maintain healthy
relationships with patients and also detail different tests that are commonly implemented. These tests allow for doctors to determine a patient's
well–being and follow the necessary steps to improve the state of their eyes. Clinical Procedures for Ocular Examination is a viable tool that can be
used to manage a patient's complaints and general health history, and assess which phases of examination and problem–specific testing should be
implemented. There... Show more content on Helpwriting.net ...
Since its creation in 1888, this company has been dedicated to "accelerate learning through intuitive, engaging, efficient and effective experiences –
grounded in research" (mheducation.com). Once again, because of the esteem and reverence of its publisher, Clinical Procedures for Ocular
Examination has had its content and reliability reinforced. This book consists of several chapters that help outline the best ways to maintain a
functional and healthy work environment. The first chapter does by explaining the best ways to treat and communicate with your patients. It
emphasizes the importance of communication and making sure the patient feels welcome, is well–informed about whatever issues they may have, and
has their questions fully and accurately answered (Kurtz 3) . The main points in this chapter are as follows: relating effectively and sensitively to
patients, conveying compassion and empathy, perceiving verbal and non–verbal communication from patients, eliciting information from patients and
observing changes in mood and activity, communicating quickly, effectively and efficiently, reading and legibly recording observations and test results,
and completing assignments, patient records, and correspondence accurately (Kurtz 2–23). Another important component this chapter covers is how to
analyze a patient's case history and assimilate it with their symptoms. A case history is a record of a

Stereopsis Impairment
Stereopsis is an impairment that prevents those who have it from seeing clearly. Stereopsis vision can be described as viewing an image during the
presence of aberrations. The apparatus is a tool that can give the viewer the ability to see one clear image when confronted with images that are
shown to be of slightly different angles. The author of this article believed that if the apparatus can be operated to converge two images then more
information may be obtained relating to the association of binocular vision and stereopsis impairment. By obtaining this information it is possible that
Stereopsis Impairment can be cured for those who have it. It is important to be able to cure the impairment that has been affecting lives for years.
To complete this experiment a variety of materials were used. A liquid–crystal–on–silicon spatial light modulator, LCoS–SLM, was used as the phase
manipulating device. This modulator contains a liquid crystal layer which was put between a transparent electrode and a silicon wafer with an array
of 800 x 600 pixels.A wavelength of ... Show more content on Helpwriting.net ...
The Dependent Variable is the change in Stereo–acuity of the subjects between the two machines under the influence of binocular aberration
combinations and normal viewing conditions. The basic components of the BAOVS remained constant. For example, the light– crystal–on–silicon
spatial light modulator. The control group used a Binocular Adaptive Optics Visual Simulator ( BAOVS) to test the stereo–acuity of their subjects. The
experimental group used a modified version of the BAOVS, which is more compact, does not include a wavefront sensor, does not include a Badal
optometer, and the stimuli are presented within a pair of internal

Visual Acuity Research Paper
What is visual acuity?
Visual acuity is commonly referred to as the clarity of vision and is dependent on both optical and neural factors, such as the sharpness of the retinal
focus in the eye, the health of the retina, and the sensitivity of the brain. One aspect of visual acuity is the ability of recognizing and discriminating
the colours of the visible spectrum of light. There are two types of cells involved in vision: rod cells and cone cells. Rod cells are highly sensitive cells
that allow for low–acuity vision in dim lit environments, however they lack the detail and colour information. Cone cells are high–acuity cells that
provide colour information in well–lit environments. Rod cells provide more convergence than the cone cells which results in their increased
sensitivity but also results in the decreased acuity.
Physiology behind differences in visual acuity in men vs women
It is generally believed that woman have higher discriminatory abilities with respect to naming of colours, which often implies they have superior
colour vision. It has been found in many studies that women perform better than men in the matching of colours from memory, and tend to use a
plethora of different words to describe sets of colour stimuli. It is possible that there exists an underlying physiological explanation for why there
should be ... Show more content on Helpwriting.net ...
This means that the separation of the colours (particularly red) will be affected depending on whether the serine or alanine pigment variants are
expressed. It has been found that these variants can actually result in measured differences in spectral separation (Rodriguez–Carmona et al, 2008). In
males which have a single X–chromosome approximately half will have the alanine L cone pigment and the other have will have the serine L cone
pigment (Murray et al,

A Brief Look at Antiangiogenic Therapy
Although laser photocoagulation and PDT destroy pathological vessels, they neither extenuate the primary angiogenic stimuli nor prevent the
development of new vessel. Antiangiogenic substances are able to resolve these problems. Antiangiogenic therapy prevents recurrence of AMD by
reversing the CNV lesions. Pegaptanib (brand name: Macugen) was the first intravitreal pharmacotherapy approved by the FDA in 2004. It binds to
VEGF165 and is responsible for "blood–retinal barrier breakdown and pathological intraocular neovascularisation", subsequently inhibiting
pathological leakage and angiogenesis. According to the results of the
VEGF Inhibition Study in Ocular Neovascularisation (VISION) trial, pegaptanib is proven to be an effective therapy for wet AMD. However,
reinjections have to be done regularly as the molecule of pegaptanib is degraded enzymatically by intraocular nucleases. Endophtalmitis, traumatic lens
injury and retinal detachment were also observed in the patients receiving this treatment.
In 2006, FDA approved the usage of ranibizumab (brand name: Lucentis), a humanized monoclonal antibody fragment that has a high affinity for
VEGF, as a therapeutic option for wet AMD. Ranibizumab is different from pegaptanib as it is not restricted only to binding VEGF165 isoform but
binds to all human VEGF isoform. It reduces leakage in vessels as well as decreases retinal and choroidal neovascularisation in animal models. The
findings of MARINA study demonstrated that

Reduced Visual Acuity Summary
Summary
Reduced visual acuity can be addressed through a range of options, including: familiarizing the student with their task and environment moving the
student closer to the object(s) and vice–versa, increasing contrast between the object(s) and background, appropriate lighting, and having an organized
environment with contrasting color to highlight areas like stairs and doorways
For students with reduced visual acuity, use of corrective lenses; sunglasses with photogrey lenses; and turning away from, or repositioning the light
source can be effective methods for addressing reduced visual acuity
Central visual field loss can be addressed through: non–optical magnification; an organized and visually simplified environment; if there is glare –
appropriate illumination to better see color or less; use of non–optical magnification
For students – central visual ... Show more content on Helpwriting.net ...
Peripheral visual field loss can be addressed by: helping the student acquire more awareness of their environment, using visual cues to help with
organization; utilizing tinted glass or mini–blinds, using additional and glare–free illumination; and allowing extra time for light/dark adaptation and
time to complete tasks
For students with peripheral visual field loss, use of a long cane can help identify edges of an object and/or utilizing sun wear or preferential seating to
reduce glare and enhance acuity
Cortical (cerebral) visual impairment can be addressed through: having an environment that is visually simplified and well–organized, with visual cues
to denote sections of the room; presenting visual information to a student slowly, while allowing adequate response time for visual processing and
integration of information using more than one sense, such as smell or touch; using objects that visually engage the student (such as red or yellow
colors, or favorite toys)
For students with cortical visual impairment, use of mnemonics or a mobility device – such as a long cane can be

Case Study Of Retinitis Pigmentosa
Objective :
To provide education, awareness, medical information and medical knowledge on low vision assessment in Retinitis Pigmentosa.
Introduction : Retinitis Pigmentosa is a group of inherited diseases that damage the light–sensitive rods and cones located in the retina, the back part of
our eyes. Rods, which provide side and night vision are affected more than the cones that provide color and clear central vision. The prevalence of
Retinitis Pigmentosa worldwide is approximately one in 4000. Up to one–quarter of all patients with Retinitis Pigmentosa will become legally blind in
both eyes, it is rare to lose all vision. More than half of all patients with Retinitis Pigmentosa have visual acuity of 20/40 or better in at least one eye. ...
Show more content on Helpwriting.net ...
Visual Field Assessment to assess the patient's peripheral vision. Central and peripheral visual field defects can be detected by performing
confrontation visual field test and amsler or threshold amsler grid assessment. Supplemental testing such as contrast sensitivity testing, glare testing,
Visual Evoked Potential (VEP), Electroretinogram (ERG), Electrooculogram (EOG) and color vision testing is done for Retinitis Pigmentosa patient.
Low Vision exams involve more test than standard examination, hence its more time–consuming. Based on the low vision examination, low vision
specialist will make suggestion for optical aids or techniques for adjusting to daily life

Amblyopia Research Paper
AAO
Amblyopia is a unilateral Of, less commonly, bilateral reduction of best–corrected visual acuity that cannot be attributed directly to the effect of any
structural abnormality of the eye or the posterior visual pathways. Amblyopia is caused by abnormal visual experience early in life resulting from one
of the following: strabismus anisometropia or high bilateral refractive errors (isometropia), stimulus deprivation
Amblyopia is responsible for more unilaterally reduced vision of childhood onset than all other causes combined, with a prevalence of 2%– 4% in the
North American population. This fact is particularly distressing because, in principle, most amblyopic vision loss is preventable or reversible with
timely detection and appropriate ... Show more content on Helpwriting.net ...
Force use of the poorer eye by limiting use of the better eye.
Cataract Removal
Cataracts capable of producing amblyopia require surgery without unnecessary delay. In young children, amblyopia may develop as quickly as 1 week
per age of life. Removal of Visually Significant congenital lens opacities during the first 4–6 weeks of life is necessary for optimal recovery of vision.
In symmetric bilateral cases, the interval between operations on the first and second eyes should be no more than 1– 2 weeks. Acutely developing
severe traumatic cataracts in children younger than 6 years should be removed within a few weeks of injury, if possible.
Refractive Correction
In general, optical prescription for amblyopic eyes should be based on the refractive error as determined with cycloplegia. Because an amblyopic
eye's ability to control accommodation tends to be impaired, this eye cannot be relied on to compensate for uncorrected hyperopia as would a normal
child's eye. Refractive correction for aphakia following cataract surgery in childhood must be provided promptly to avoid compounding the visual
deprivation effect of the lens opacity with that of a severe optical deficit. Both anisometropic and ametropic amblyopia may improve or resolve with
refractive correction alone over several

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