Trifocals are eyeglass lenses that correct vision at three distances: distance, intermediate, and near. They were patented in 1827 and are meant for occupational use rather than general wear. Trifocals have three focal points to correct distance, intermediate vision used at arm's length, and near vision for reading. Common professions that use trifocals include electricians, librarians, and musicians. Trifocals come in several styles like split, cemented, fused, and solid trifocals. They are dispensed by positioning the intermediate portion between the distance and near portions.
Contact lens for congenital aphakia and other eye conditions for infants and toddlers. The slide presentation encompasses indications for CL fitting in paediatric, contact lens options, fitting techniques, challenges and contact lens as myopia control.
Contact lens for congenital aphakia and other eye conditions for infants and toddlers. The slide presentation encompasses indications for CL fitting in paediatric, contact lens options, fitting techniques, challenges and contact lens as myopia control.
Troubleshooting bifocals and Market Availability in Nepal
Bifocals in Anisometropia
Prismatic Effect in Bifocal
Bifocal Prescription
Bifocals in High Astigmatism
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. :)
A basic view of fundamentals of lens in photography. Discusses various aspects of lens, types of lens and which lens suitable for various photography moments. Hope you find it useful
Troubleshooting bifocals and Market Availability in Nepal
Bifocals in Anisometropia
Prismatic Effect in Bifocal
Bifocal Prescription
Bifocals in High Astigmatism
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. :)
A basic view of fundamentals of lens in photography. Discusses various aspects of lens, types of lens and which lens suitable for various photography moments. Hope you find it useful
INTRODUCTION TO CAMERA LENS AND IMAGE QUALITY TESTING Luxman Singh
CAMERA WORKING AND DATA FLOW
THE LENS AND TYPE OF LENSES
EXPOSURE TRIANGLE
APERTURE
SHUTTER
ISO
CAMERA IQ TESTING PROCESS
CAMERA ADB COMMANDS AND INPUT KEY EVENTS
In what context The Achilles Heel term used in imaging field .pdfarihantmobilepoint15
In what context \"The Achilles\' Heel\" term used in imaging field? Explain in details.
Solution
The greatest thing about interchangeable camera lenses is the variety of optical designs, from
ultrawide to supertelephoto and everything in between, that offer an incredible amount of variety
for visual expression, creativity, and optical performance optimized for different photographic
situations. And while it may be sometimes completely and totally obvious what types of
photography a certain lens excels at—for example, everyone knows that Macros are designed to
capture close-up details; telephoto lenses are great for long-reach wildlife and sports from the
sidelines—many styles of camera lenses have lesser-known secret superpowers that can be called
upon to make a photo. Let’s take a look!
Supertelephoto lenses
Long lenses, like the Sigma 150-500mm F5.6.3, or 300-800 F5.6 to name two, are known to be
great for making sports and wildlife images. Wide open, these lenses can isolate the subject from
the background to really make the images pop. And of course, the wide apertures which give
very shallow depth of field feel also yield the fastest shutter speeds, which are necessary to
freeze a bird in flight, or an athlete on the move.
Everyone knows supertelephoto zoom lenses are great for long-reach photography at widest
apertures for freezing active subjects, like wild birds, with fast shutter speeds. Here, the Sigma
150-500mm is trained on an American Anhinga, at 500mm, wide open at F6.3.
And Landscape, or should we say sky-scape, photographers also know that longer focal lengths
also can make for huge suns and moons, the effect of which is amplified when the celestial orb is
near earthbound features in the frame.
Longer lenses can make the sun and moon much more prominent in the frame. Again, this was
captured with the 150-500mm at 500m. 1/500 F6.3 ISO 100.
The Lesser-known superpower of supertelephoto lenses: distance compression
When supertelephoto zoom lenses are stopped down to smaller apertures, and focused at a longer
distance, depth of field is increased, and the apparent relationship of distance between objects in
the frame appears much more compressed than in a standard field of view.
When you use smaller apertures with supertelephoto lenses, you can compress the expression of
distance. It can be used for much more exciting purposes than showing some afternoon
downtown traffic; but this image illustrates the effect with objects of touchstone size. Everyone
know about how big a car, traffic light, and two story building is, so this offers an understandable
sense of scale. This image was shot at 500mm at F/13, to maximize depth of field while
managing diffraction. The next image shows a map view with the distance between objects in the
frame.
This Google Earth view shows that it is is just over one thousand (1,000) feet from my capture
position to the hotel in the background. The yellow line shows the relationship of the objects in
the fr.
progressive lenses, multifocal lenses, polyfocal lenses, lenses for presbyopia, bifocal lenses, lenses for near reading, lenses for the elderly, above age 40
Deviprasad Goenka Management college of Media Studies
http://www.dgmcms.org.in/
Subject:Photography
Lesson 1:Types of Lens , Mega Pixel , Image Quality .
Faculty Name: Partha Pratim Samanta
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
2. OUTLINE
INTRODUCTION
HISTORY OF TRIFOCALS
TRIFOCALS VS BIFOCALS
PURPOSE OF TRIFOCALS
TYPES OF TRIFOCALS
DISPENSING TRIFOCALS
ADVANTAGES AND DISADVANTAGES
3. INTRODUCTION
Based on the number of focal points, ophthalmic lenses are divided
into four types
Single vision lenses
Bifocals
Trifocals
Progressive addition lens
4. SINGLE VISION LENSES - Corrects only one vision at a time .
(Single focal point)
BIFOCALS – Corrects two vision, Distance and near.(Two focal
points)
TRIFOCALS – Corrects three vision, distance, near and
intermediate.(Three focal points)
PROGESSIVE – Corrects different distances.(Many focal points)
5. MULTIFOCALS
TRIFOCALS - are eyeglass lenses that enable you to see clearly at
three different distances ( Distance zone -far, intermediate zone –
arm’s lenght , near zone – reading )
PROGRESSIVE – are eyeglass lenses that enable you to see all the
distances clearly.
6.
7. HISTORY OF TRIFOCALS
Trifocals, patented in 1827 by John Isaac Hawkins, are eyeglasses
with lenses that have three regions which correct for distance,
intermediate, and near vision.
Trifocal lenses are designed for performing a particular job or hobby
and are not meant for general-purpose wear.
8. Corrects two
zones of
vision.
It has two
focal points.
BIFOCALS
Corrects
three zones
of vision.
It has three
focal points.
TRIFOCALS
9. PURPOSE OF TRIFOCALS
A multifocal lens that has a specific purpose, or is created to perform
a specific job, is called an occupational lens.
If the eye has sufficient accommodation , it may view these objects
which lie at an intermediate. But at the certain stage in presbyopia
accommodation become insufficient that a third pair of spectacles Is
required exclusively for intermediate use.
What makes these lenses different from other lenses is that the
near, intermediate and far zones for vision are placed on specific
areas of the lens, which makes vision for these particular tasks
easier.
15. PROFESSIONS DISTANCE INTERMEDIATE NEAR
ELECTRICIAN To see the switches
whether it ON or
OFF
To take the tools
like srewdrive ,
pliers etc
To join the wires,
fit fan, light.
LIBRARIAN To see the upper
shelf and books
For arranging the
books
For reading the
books and writing
AIR HOSTESS To see the
passengers seated
at the last row
To place the
passengers Luggage
To serve the
passengers
MUSICIAN To see the audience To see the musical
notes
To play the
instruments
SHOPKEEPER To see the products
in upper shelf
To see the computer
for billing
To see the product
details
16. POSTION OF THE INTERMEDIATE
PORTION
Usually in between distance and near , it can be positions according to
the requirements of the patients
For example : Electrician , pilots, dentists , artists , musicians
17. The power which must be added to the distance prescription to
produce the intermediate prescription is called the intermediate
addition. ( + 0.75 DS to + 2.00 DS )
INTERMEDIATE ADDITIONS may range from about 50 % - 70 %
that of the reading addition.
18. The IP addition can be given as a ratio of the RP addition expressed
as %
This is called IP/RP ratio :
IP/RP ratio = Intermediate addition
Reading addition
100
19. Scenario 1
The patient is a carpenter who works mostly at arm's length or closer.
Distance is less important and he has another pair of spectacles for
general wear. He cannot be dispensed a progressive lens as true
straight lines are important.
Distance power +2.00DS
Inter power (50%IP/RP) +1.50 (+3.50DS)
Reading add +3.00 (+5.00DS)
20. COMPUTER USER ??
If I moved my computer monitor close enough to see the screen
clearly, it was nearly in my lap. If I left the monitor where it should
be, I had to lean forward awkwardly. During my annual eye exam , I
told my optometrist about my workstation discomfort and the strain
that was causing my eyes. I optimize my work environment for
comfort and still have problems.
the solution may be another pair of glasses
21. Scenario 2
The patient needs the shorter IP/RP ratio, for computer use for
example.
Distance power +2.00DS
Inter power (66%IP/RP) +2.00 (+4.00DS)
Reading add +3.00 (+5.00DS)
24. SPLIT TRIFOCALS
Same as franklin type bifocals
Different power lenses were cut and fitted into the single frame.
Advantages:
- Different powers and high additions are possible.
- Intermediate portion can be positioned anywhere in the frame.
Dis-Advantages:
-Cosmetically poor because of lens attachment and the attachment
space will attract dirt
-Difficult to fit into the frame
26. CEMENTED TRIFOCALS
Small segments of different powers will be cemented to the main lens
Advantages:
-Any powers are possible
-looks better than split trifocals
-Any designs are possible i.e the trifocal segments can be positioned anywhere
in the lens
Dis-Advantages:
-Cemented segments might fall or looks faded.
28. FUSED TRIFOCALS
Common type nowadays
Same like fused bifocals, composite buttons with different materials
will be fused on to the main Distance Portion Lens
Here the Intermediate portion is positioned in between Distance and
Reading portion
And IP is 7 to 8 mm deep
Advantage:
Invisible Segments so – cosmetically looks good.
33. Solid trifocals
The name SOLID – because all the distance, Intermediate and
Reading portions made from the same material and Single Blank with
different radius of curvature.
TYPES ARE : Up and downcurve , concentric and band trifocals
34.
35. COMBINATION OF TRIFOCALS
Occasionally combination of Trifocals can be manufactured
For eg: Fused Intermediate Segment on the Solid Bifocal
36. Dispensing trifocals
Trifocals are normally fitted so that the lower limbus of the cornea is
at the centre of the intermediate portion with eyes in the primary
position
FITTING – Generally fitted 2mm below the bottom of the pupil
It can be set at a non-standard height, depending upon the patients
requirements
Size , position and height of the segment depends upon – Occupation
and intermediate demand