Binocular vision refers to the coordinated use of both eyes to produce a single mental impression. It develops through childhood as the visual and motor mechanisms mature. Theories of binocular vision aim to explain how a single visual percept is formed from two retinal images. Key components include retinal correspondence, the horopter curve, and Panum's fusional area. Abnormalities can disrupt binocular vision and cause issues like diplopia or suppression. Clinical tests evaluate retinal correspondence, stereopsis, and fusional abilities to assess binocular function.
Detailed instumentaion and use of manual Lensometer and just a outline of automated lensometer.
I have used the picture of manual lensometer with out the parts describtion because i have explained orally by showing the picture..
Hope u all like it and may help you in learning better. :)
Scleral lens is a large rigid contact lens with a diameter range of 15mm to 25mm. Its resting point is beyond the
corneal borders, and are believed to be among the best vision correction options for irregular corneas. Wearing scleral lens also can postpone or even prevent surgical intervention as well as decrease the risk of corneal scarring.
Detailed instumentaion and use of manual Lensometer and just a outline of automated lensometer.
I have used the picture of manual lensometer with out the parts describtion because i have explained orally by showing the picture..
Hope u all like it and may help you in learning better. :)
Scleral lens is a large rigid contact lens with a diameter range of 15mm to 25mm. Its resting point is beyond the
corneal borders, and are believed to be among the best vision correction options for irregular corneas. Wearing scleral lens also can postpone or even prevent surgical intervention as well as decrease the risk of corneal scarring.
Binocular single vision (BSV) is the ability to use both eyes together to achieve a single fused percept, even in the presence of disparity of the image seen by each eye. It is divided into five grades: simultaneous perception, superimposition, sensory fusion, motor fusion, and stereopsis.
The current study aimed to examine the contribution that motor fusion and stereoacuity make to visuomotor task performance, while addressing some of these confounding factors. Individual differences in task performance and adaptation to BSV deficits were minimized using a repeated measures design, in which participants with normal BSV and no amblyopia or strabismus had their fine visuomotor task performance assessed as their BSV was progressively degraded.
It details about the sensory development, theories and the neural aspects of binocular vision development along with various tests involved to assess stereopsis.
This Pdf is about the physiology of binocular vision. It describes each grades of binocular vision namely; simeltaneous perception and superimposition, sensory and motor fusion and stereopsis. It describes different theories of development of binocular vision. It also describes principal visual direction, oculocenteric localization, egocenteric localization, normal retinal correspondence and anomalous retinal correspondence, horopter, panum's fusional area, crossed and uncrossed physiologic diplopia, types of suppression, retinomotor value, binocular rivalary, pathologic diplopia and confusion.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
2. DEFINITION
NORMAL BINOCULAR VISION
DEVELOPMENT OF BINOCULAR VISION
THEORIES OF BINOCULAR VISION
MECHANISM OF BINOCULAR VISION
GRADES OF BINOCULAR VISION
ABNORMALITIES OF BSV
CLINICAL TESTS FOR BSV
TO THE SEMINAR
3. DEFINITION
• State of simultaneous vision
with two seeing eyes that
occurs when an individual
fixes his visual attention on an
object of regard.
• It is the co-ordinated use of
both eyes to produce a single
mental impression.
4. Pre-requisites for development of BSV
Motor Mechanism:
•Correct neuromuscular development so that the visual axes
are directed at the object (FIXATION)
•Overlap of visual fields
Sensory Mechanism:
•Approximately equal image clarity and size in the two eyes
•Corresponding retinal areas (cyclopean eye)
•Normal visual pathways
Mental Process:
•Ability of visual cortex to promote binocular single vision
5. Why to study binocular vision?
• The basic laws of binocular vision forms the very
foundation on which our current understanding of
strabismus and its symptoms and sensory
consequences is based.
• Knowledge on BSV forms basis to orthoptic
treatments & many physiological processes in the eye.
6. DEVELOPMENT OF BINOCULAR
VISION
2 to 3 weeks turning head to fixate an object
4 to 5 weeks sustain monocular fixation of large near objects
3 months binocular fusion
3 to 6 months stereopsis
1 YR Fusional movements firmly established
2-3 yr Adult level visual acuity reached
7. 1. Theory of correspondence and disparity
(most widely accepted theory)
2. Neurophysiological basis
3. Alternation theory of Binocular Vision
4. Projection theory of Binocular Vision
5. Motor theory
6. Theory of isomorphism
Theories of BSV
Older theories
8. Theory of correspondence and disparity
-Simultaneous stimulation of the corresponding points by
one object transmits single visual impression with no depth
quality.
-Simultaneous stimulation by two object points that differ in
character results in binocular rivalry.
-Diplopia occurs when disparate elements are stimulated by
one object.
- Binocular single vision with stereopsis results when the
horizontal disparity remains within the limits of Panum’s
area.
9. NEUROPHYSIOLOGY OF
DEVELOPMENT
2 different visual pathways from different population of retinal
ganglion cells.
Parvo and Magno cellular pathway- lateral geniculate body.
P cells- colour, fine 2 point discrimination and project to the
areas of fovea
M cells- direction, motion, speed, flicker, gross binocular
disparities. Project to the areas of Parafoveal and peripheral
retina
In striate cortex- p & m-recipient lamellae are segregated. M
cells go predominantly to parieto-occipital areas, P cells to
temporo-occipital areas. But there are inter-connecting
pathways, so information overlaps.
10. MECHANISM OF BINOCULAR
VISION
• Visual axis
• Retinal correspondence
• Egocentric localisation
• Horopter
• Pannums fusional area
13. OCULOCENTRIC
(MONOCULAR)
• When an object is viewed, its image falls on the
foveola. visual direction -represented by principle
visual line or axis
• Each point on retina can have its own visual axis
• For a given eye position , objects having
superimposed retinal images will be seen in as
being in alignment in visual field (law of OC visual
direction)
14. EGOCENTRIC (BINOCULAR)
• Frame of reference(single system of VD) is head
(egocentric) rather than 2 eyes.
• Visual space is seen with imaginary single
eye(cyclopean eye)
• Herring’s law of identical visual direction – fovea
have a common subjective visual direction.
15. RETINAL CORRESPONDENCE
• Correspondence- relative localisation of objects in space to each
other under binocular conditions.
• Fovea determines the principle visual direction
• Both fovea has same space value i.e. ‘ZERO’ (principal VD)
• Each receptor under monocular condition dictates visual
direction in relation to fovea
• Images falling on corresponding locations in each eye creates
single mental impression.
• Acc. To BAGOLINI it’s area to area relationship not point to point
relationship
16. HOROPTER
• Introduced in 1613 by Aguilonius
• Approached mathematically by Helmholt
• Means ‘Horizon of vision’
• Locus of all object points that are imaged on corresponding
retinal elements at a given fixation distance.
• Different horopter for each fixation distance
17. VIETH-MÜLLER CIRCLE
o Theoretical or mathematical horopter curve
o If corresponding points have a geometrically
regular horizontal distance from the two retinas,
the longitudinal horopter curve would be a circle
passing through the center of rotation of the two
eyes and the fixation point
18. EMPIRICAL HOROPTER CURVE
• Hering and Hillebrand could show that the Vieth-
Müller circle does not describe the longitudinal
horopter.
• Empirical horopter curve is flatter than the Vieth-
MÜller circle
• Distribution of the elements that correspond to each
other is not the same in the nasal and temporal parts
of the two retinas
20. PANUM’S AREA
• Panum, the Danish physiologist, first reported this
phenomenon.
• Region in front and back of the horopter in which
single vision is present is known as Panum’s area of
single binocular vision or Panum’s fusional area
• Horizontal extent of these areas is small at the
center (6 to 10 minutes near the fovea)
• Increases toward the periphery (around 30 to 40
minutes at 12° from the fovea)
22. Physiological Diplopia
The Diplopia elicited by an object
point off the Pannum’s fusional
area
Types
A.Crossed (Heteronymous) Diplopia
Temporal (crossed) disparity
B.Uncrossed (homonymous)
Diplopia
Nasal (uncrossed) Disparity
23. Fixation Disparity
It is the minute image displacement, rarely exceeding
several minutes of arc of angle, occurs within
Panum’s space while fusion is maintained.
• Due to presence of pannum’s fusional area
– A physiological variation in placement of retinal image
displacement from corresponding retinal points
• Even Allow fusion
• Displacement of retinal images in two eyes
– Retinal disparity
25. SIMULTANEOUS
PERCEPTION
Simultaneous perception exists when signals transmitted from the
two eyes to the visual cortex are perceived at the same time.
It consists of the ability to see two dissimilar objects simultaneously.
• Does not imply that both eyes see same object.
• Does not imply superimposition of both objects.
“Power to see 2 dissimilar objects simultaneously”
Ceases only when we suppress the image from one
eye at will.
26. FUSION
• 2nd Grade of Binocular Vision
• Ability of the eyes to produce a composite picture
from two similar pictures, each of which is
incomplete in a small detail.
• It is not superimposition of dissimilar pictures
27. Components of fusion
Sensory Fusion
the unification of visual excitations from corresponding retinal images into a
single visual percept, a single visual image
The ability to unify images falling on corresponding retinal areas.
Motor Fusion
It is a vergence movement that causes similar retinal images to fall and be
maintained on corresponding retinal areas.
Ability to align the eyes in such a manner that sensory fusion can be
maintained
Diplopia preventing mechanism
The normal fusional range is 35/40 PD base out and 16 PD base in on near
reading.
16PD base out and 8PD base in on distance testing.
28. STEREOPSIS
• 3rd Grade of Binocular Vision
• Visual appreciation of three dimensions
• Ability to obtain impression of depth by superimposition of
two images of the same object, seen from 2 slightly different
angle.
• Retinal disparity (Fixation disparity) is the basis of 3 D
perception
• Stereopsis occurs when Retinal disparity is not large enough
for simple fusion but small enough to cause diplopia
Not similar to depth perception.
29. ADVANTAGES
1. Optical defects in one eye are made less obvious by the normal
image in the other eye
2. Defective vision in one part of the visual field is masked
because the same image falls on the functioning area of the
other retina.
3. Field of vision is definitely larger.
4. Allow the individual to converge the line of sight and obtain a
reading as to the absolute distance of objects.
5. Presence of stereopsis.
30. PERCEPTION OF DEPTH
• Perception of distance of objects from each
other or from the observer.
• Several clues contribute-
A] BINOCULAR CLUE: Stereopsis.
B] MONO OCULAR CLUES:
31. Monocular./Non Stereoscopic
Clues
a) Parallactic movements
b) Linear perspective
c) Overlay of contours
d) Size
e) Distance from horizon
f) Distribution of highlights & shadows
g) Aerial perspective
32. PARALLACTIC
MOVEMENTS
Most important in depth perception next to stereopsis
Slight shift of head while fixation is maintained results
in change of relative position of objects in gaze
Objects beyond fixation point – move in same direction
Objects closer – move in opposite direction
35. Advantage of having BSV
• Stereopsis
• Binocular summation.
– vision shaper, clearer &
more sensitive
• Larger field of view.
• Spare eye
visual field
37. Anamolies of binocularity
Confusion
When squinting occurs the two foveas view two different
objects that are physically separated in objective space,
and send two different images to a single cortical
perceptual area. This leads to confusion.
Diplopia
When squinting occurs an object in space is perceived by
the fovea of one eye and some other extra-foveal point of
the other eye, which has a different projection or
localization value in space. Thus an object would be
localized twice in space causing diplopia.
38. Conclusion
• Without the basic concepts of BSV it is almost
impossible to understand strabismus and treat it.
• The advantage of BSV outweights the
disadvantage.
39. CLINICAL TESTS
• For retinal correspondence
• For supression
1.Red filter test
2.Worth FDT
3.Bagolinis striate glass test
4.After image testing
40. • Tests for stereopsis
Qualitative
Random dot stereograms
Synaptophore
Quantitative
Titmus fly test
TNO test
Lang test
44. Stereopsis testing
• Stereo acuity is a quantitative measure of stereopsis, it
represents the smallest horizontal retinal image
disparity that give rise to a sensation of depth.
• Stereopsis is measured in seconds of arc.
• 1degree=60minutes of arc, 1minute=60seconds of arc.
• Normal stereoacuity= <60seconds of arc.
45. FEATURES FOR
STEREOPSIS TEST
• EYES MUST BE DISSOCIATED
• MUST BE PRESENTED WITH SEPERATE FIELD OF
VIEW
• EACH FIELD MUST CONTAIN ELEMENTS IMAGED
ON CORRESPONDING RETINAL AREAS
46. VECTOGRAPH TEST - TITMUS
STEREO TEST
It consists of Polaroid material on which the two targets
are imprinted
Each target is polarized at 90 degree with respect to the
other.
Use of polaroid spectacles.
It is a 3D Polaroid vectograph which is made up of two
plates in a form of
booklet.
Advantages : simple and easy to perform.
Disadvantages : unreliability in differentiating patients
with amblyopia and
heterotropia