This document discusses visual impairment, including defining normal vision and levels of severity of vision impairment. It covers causes such as inherited conditions, infections, age-related issues, injuries, and more. Diagnostic tests are mentioned including visual acuity, visual field, and tonometry tests. Treatment options include controlling diabetes, cataract surgery, magnification systems, glaucoma drugs, and optical aids. Prevention focuses on regular eye exams, protecting eyes from sun damage, and being aware of family history of eye diseases.

1. VISUAL
IMPAIRMENT
BY: MUKESH JANGRA
M.Sc.NURSING I YEAR
SVBCON, SILVASSA

2. Course outlines……
• At the end of the teaching, you will be able to
know about..
 what are thevisual impairments
 types and levels
 etiology and risk factors
 patho-physiology
 signs and symptoms
 diagnostic screening
 management and nursing roles.

3. VISUAL IMPAIRMENT

4. What is vision ?
• Vision occurs when images (visual stimuli) are
received by the eye and transmitted to the
brain. Vision is a complex process that
involves the eye, the brain, and the pathways
between them.

5. What is normal vision ?
• When describing vision, most people tend to
think of good (or “normal”) vision as the
ability to see clearly at all distances without
glasses. This is commonly referred to as
“20/20” vision.

6. What is vision impairment?
• Vision impairment is the loss of some aspect of
vision that reduces a child’s ability to see.
Vision impairments range in severity from
mild vision loss to total absence of light
perception.

7. Levels of Severity of Vision Impairments
Level of Severity
• Normal vision
• Near normal vision
• Moderate low vision
• Severe low vision
• Profound low vision
• Near total blindness
• Total blindness
Best Correctable Snellen
Acuity Equivalent1
• 20/25 or better
• 20/30 to 20/60
• 20/70 to 20/160
• 20/200 to 20/400
• 20/500 to 20/1,000
• less than 20/1,000
• No light perception (NLP)

8. Classification According To Severity
Mild Visual Impairment
Moderate Visual Impairment
Severe Visual Impairment

9. 1. MILD VISUAL IMPAIRMENT
• Can read relatively larger characters
• No difficulty in identifying shapes, colours
and brightness contracts

10. 2. MODERATE VISUAL IMPAIRMENT
• Can tell shapes and colours of objects and can
distinguish between brightness and darkness.
• Can only read characters with larger size and
broader strokes.

11. 3. SEVERE VISUAL IMPAIRMENT
• Can only distinguish more obvious changes in
brightness and darkness.
• May not see anything (completely blind).

13. DAILY ACTIVITIES:
Squinting to get an object in
focus, Trouble locating familiar
objects in a familiar environment,
Wearing mismatched clothing.
MOBILITY:
Leaning against the wall when
walking , Running into objects,
Difficulty walking on uneven
surfaces.

14. EATING/DRINKING:
Difficulty getting food onto a
utensil and serving from a platter,
Frequently spilling food
READING/WRITING:
Difficulty writing on the lines of a
piece of paper, Frequent
complaining that the lighting is
inadequate for reading or writing

15. CAUSES

16. 1. Inherited
conditions of
blindness and
vision impairment
2. Infections of the
eyes
3. Age related visual
impairment

17. Injury to Eyes Amblyopia
Cataract

18. Trachoma Diabetic retinopathy

19. Cancer of eyes

20. EPIDEMIOLOGY
• By age: More than 82%
of all people who are
blind are 50 years of age
and older. 1.4 million
blind children below age
15.

21. • By gender: females have a significantly
higher risk of being visually impaired than
males.
• By geography: . More than 90% of the
world's visually impaired live in developing
countries.

22. DIAGNOSTIC EVALUATION

23. Tests for visual impairment
1. Snellen test
• Also known as the visual
acuity test.
• Snellen’s chart is used.

24. 2. Visual field test
• A person can see without tilting or
turning one’s head.
• This measures the peripheral vision of the
eyes.

25. 3. Tonometry test
• Uses specialized instruments to determine
fluid pressure inside the eye to evaluate for
glaucoma.

26. 4. Ocular Motility Assessment
• This tests if there is squint of other
problems in the movement of the
eyeballs.

27. Other tests:
• Visually evoked potential
(VEP)
• Electroretinogram (ERG)
• Electro-oculogram (EOG)

28. TREATMENT

29. • Control of diabetes
• Cotaract surgery
• Magnification systems
• Glaucoma
• Drugs: The drugs may
include Beta-blockers
like betaxolol hydrochloride
or carbonic anhydrase inhibitors dorzolamide and
Sympathomimetics like brimonidine tartrate.

30. Optical aids
• -Improving far sight:
TV,Theater, Cinema
• -Improving near sight:
Reading, Writing, Crafts
• -Improving sensitivity
to contrast:Special
lights,Magnified
games,Watches,special phones,
etc.

31. PREVENTION

32. • Regular eye examinations:
Most people should have their eyes tested at
least once every two years.
It is very important for drivers and people
whose eyesight may be affected by their
occupation, such as those who use computer
monitors, to have regular eye examinations

33. Children should also have regular eye
examinations.
- The Health Service Executive (HSE) is obliged
to provide optical services free of charge to
certain groups.

34. There are several other ways to reduce the risk
of visual impairment:
• Protect your eyes from the sun. Ultra violet
(UV) rays from the sun can damage your
eyesight so in bright sunlight, wear a pair of
good-quality sunglasses that protect your eyes
from both UVA and UVB rays.

35. • Find out whether there is a history of
glaucoma or eye disease in your family.
• Hypertension-Hypertension is when the
pressure of the blood in your bloodstream
is regularly above 140/90 mmHG.
• Pain- Pain is an unpleasant physical or
emotional feeling that your body produces
as a warning sign that it has been
damaged.