Visual Acuity Development and Limitations Quiz

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Questions and Answers

What is the primary function of rods in the retina?

Completely rod-free

Responsible for vision under dark or dim conditions (correct)

Contain no photoreceptors

Responsible for color vision and high spatial acuity

What is the primary function of cones in the retina?

Contains no photoreceptors

Completely rod-free

Responsible for color vision and high spatial acuity (correct)

Responsible for vision under dark or dim conditions

What is the primary reason for the yellow appearance of the macula?

Due to xanthophyll carotenoids: lutein and zeaxanthin (correct)

Due to the foveal avascular zone

Due to the presence of rods

Due to the presence of cones

Where are most cones concentrated in the retina?

Fovea centralis Signup and view all the answers

What is the angular size of the foveola?

54 minutes of arc (54’ arc) Signup and view all the answers

What is the primary reason for the blind spot in the retina?

Corresponds to the optic nerve, contains no photoreceptors Signup and view all the answers

What is the purpose of PH Pinhole Visual Acuity?

To determine if a decrease in vision is correctable by lenses Signup and view all the answers

What is the function of Vernier Acuity?

Discriminating differences in the spatial position of segments of a test object Signup and view all the answers

What is the Minimum Resolvable of Visual Acuity?

The smallest angular size at which subjects can discriminate the separation between critical elements of a stimulus pattern Signup and view all the answers

What is the purpose of Target Recognition Tasks in clinical exams?

To recognize or name a target, such as with Snellen letter Signup and view all the answers

What does Visual Efficiency quantify for legal and compensatory purposes?

The level of visual loss for legal and compensatory purposes Signup and view all the answers

What is the purpose of Minimum Recognizable Acuity in Visual Acuity?

Measuring the angular size of the smallest feature Signup and view all the answers

What is the distance at which near visual acuity is tested?

40cm Signup and view all the answers

Which method can be used for patients unable to use visual acuity charts?

Counting fingers Signup and view all the answers

What is the notation used for visual acuity that is useful for research but rarely used clinically?

Decimal acuity Signup and view all the answers

At what age do pediatric patients typically achieve matching visual milestones?

5 years Signup and view all the answers

What does a lack of improvement in visual acuity with pinhole testing indicate?

NIPH Signup and view all the answers

If a patient cannot see the 20/400 line on the Snellen chart, what type of chart can be used for testing?

Bailey Love chart Signup and view all the answers

What is the Snellen Visual Acuity method widely used for?

Measuring visual acuity in terms of the angular size of the gap for the smallest-sized letter a patient can identify. Signup and view all the answers

What is the Minimum Angle of Resolution (MAR) in relation to the Snellen Notation?

The reciprocal of the Snellen Notation, equaling the angle (arc minutes) that each stroke of the letter subtends at the person’s eye. Signup and view all the answers

What does the LogMAR specify in relation to visual acuity?

Visual acuity using a logarithmic scale, commonly used in research. Signup and view all the answers

What is the calibration of the VA chart based on?

Measuring the height of the 20/200 (6/60) letter E, ideally measuring 87.00mm. Signup and view all the answers

What does the Visual Acuity measurement procedure involve?

Testing visual acuity at distance and near with and without correction using specific equipment and procedures. Signup and view all the answers

What is recommended for testing visual acuity?

Memorizing the classical Snellen chart. Signup and view all the answers

What is the expected visual acuity at 1 month old?

20/800 to 20/200 Signup and view all the answers

What is the average axial length of the eye in adolescence to adulthood?

23-25mm Signup and view all the answers

What is the impact of refractive error on visual acuity?

1D defocus decreases VA from $20/20$ to $20/50$ Signup and view all the answers

Which method is used for assessing visual acuity in children by presenting different stimuli to each eye and observing which stimulus the child fixates on?

Preferential looking Signup and view all the answers

What is the age-related decline in visual acuity, where less than 50% retain 20/20 vision?

After age 62 Signup and view all the answers

What happens to visual acuity with retinal eccentricity, with a 60% reduction at 1-degree displacement?

Lower acuity away from fovea Signup and view all the answers

Which arcades demarcate the Macula? SELECT TWO

Superior medial vascular arcades Signup and view all the answers

Study Notes

Visual Acuity Development and Limitations

Axial length at birth: 16-17mm, 1 year old: 20-21mm, Adolescence-Adulthood: 23-25mm
Expected visual acuity at 1 month old: 20/800 to 20/200, 6-month-old: 20/20
Various methods for assessing visual acuity in children: Preferential fixation, Preferential looking, Optokinetic drum, Visual Evoked Potential
Different visual acuity charts and acuity tasks: Detection, Recognition, Resolution, Location, Target Detection
Age-related decline in visual acuity: On average, people retain 20/20 vision until age 62, after which less than 50% retain it
Factors affecting visual acuity: Refractive errors, Retinal eccentricity, Luminance, Contrast, Pupil size, Testing distance
Impact of refractive error on visual acuity: 1D defocus decreases VA from 20/20 to 20/50, hyperopes are less affected due to accommodation
Influence of retinal eccentricity on visual acuity: Lower acuity away from fovea, with a 60% reduction at 1-degree displacement
Effect of luminance and contrast on visual acuity: Increasing luminance and contrast generally improve visual acuity
Testing conditions for visual acuity: Illumination should be optimal, and room lighting in the vicinity of the chart should be low
Impact of pupil size on visual acuity: Small pupils increase depth of focus, large pupils cause spherical aberrations
Factors affecting visual acuity including exposure duration, interaction effects, and target and eye movement

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Description

Test your knowledge of visual acuity development and limitations with this quiz. Explore the expected acuity at different ages, methods for assessment, factors affecting acuity, and age-related declines. Dive into topics such as refractive errors, retinal eccentricity, luminance, contrast, and testing conditions.