introduction to low vision

8/2/2019 Introduction to Low Vision

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Introduction to Low Vision

Ifrah Bukhari

Optometrist


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What is low vision?

A level of vision that prevents a personfrom performing customary visionactivities with standard or conventional

optical correction Such patients can benefit for day-to-

day activities by exploitation of

significant usable residual vision withthe help of low vision aids


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Definitions of Low Vision:WHO Definition:

The WHO defines low vision as VA lessthan 6/18-3/60

Modified/Revised Definition:

A person with LV is one who hasimpairment of visual functioning evenafter treatment &/or standard refractivecorrection & has a VA of


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Categories of Low Vision: The International Classification of

Diseases categorizes the LV as:

* In better seeing eye

Definition Visual acuity Visual field

Moderate visual

impairment


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The threshold criteria thatdefines an individual as havinglow vision are an uncorrectable &irreversible VA of


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Blindness:

A blind person is one who is so blind asto be unable to perform any work forwhich eyesight is essential

By WHO definition a blind refers to as VA


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Partially sighted: Person may be considered as partially

sighted if he is substantially &permanently handicapped by defectivevision

Partially sighted are ones who have

some useful vision & may not beclassified as legally blind

Guideline VA levels for partial sightregistration are taken as:

1. 3/60 up to 6/60 with full field2. Up to 6/24 with moderate field

constriction, media opacities or aphakia3. 6/18 or better with gross field defect


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Impact of Low Vision:

Low vision can affect normaldevelopment & education of children &all areas of daily living, work & leisure

for adults The broad areas that LV impacts: education, work & leisure

Social & consumer interactions

Mobility

Emotional reaction to vision loss

Household & personal care


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Self evaluation Test

MCQ,s


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1. The person is considered tobe low vision patient.

A. VA of 6/18 & 6/12

B. VA of 6/60 & 6/18C. VA of 6/36 & 6/9

D. All of the above


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2. Patient is considered to be lowvision patient if

A. VF


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3. Severe visual impaired

A. VA 6/18-6/48 with VF < 5 degree

B. VA 6/60-6/120 with VF < 5 degreeC. VA 6/60-6/120 with VF < 20 degree

D. VA 6/120-6/300 with VF < 10 degree


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4. By WHO definition a blindrefers to as

A. VA


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5. The legally blind are ones who

have in the better eye bestcorrected

A. VA of 6/60 or VF of 10 degrees or less

B. VA of 3/60 or VF of 20 degrees or less

C. VA of 6/60 or VF of 5 degrees or less

D. VA of 6/60 or VF of 20 degrees or less


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Answers

1. B

2. E

3. C

4. A

5. D

introduction to low vision

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