Blindness

2. INTRODUCTION
Blindness can be temporary or permanent.
Damage to any portion of the eye, the optic
nerve, or the area of the brain responsible for
vision can lead blindness.
Blindness is a lack of vision. It may also refers to
a loss of vision that cannot be corrected with
glasses or contact lenses

3. DEFINATION
WHO definition of blindness
Visual acuity of less than 3/60 (Snellens) or its
equivalent.
In the absence appropriate vision charts (By non-
specialized personnel), the WHO has now added
the “Inability to count fingers in daylight at a
distance of 3 meters” to indicate less than 3/60
or its equivalent.

4. WORLD PROBLEM
180 million people worldwide are visually
disabled, of them 45 million are blind
• 80% of blindness is avoidable.
• Major cause of blindness and their estimated
prevalence are
– Cataract 19 million
– Glaucoma 6.4 million
– Trachoma 5.6 million
– Childhood blindness > 1.5 million
– Others 10 million
– 32% of world’s blind are aged 45-59 years 58%
are >60 years old

5. CAUSES OF BLINDNESS
According to WHO estimates in 2002, the most common cause of
blindness around the World are:
 Cataracts ( 47.9%)
Glaucoma (12.3%)
Age related- Degeneration of ocular tissue (8.7%)
Corneal Opacity (5.1%)
Diabetic retinopathy (4.8%)
Amaurosis fugax is a sudden blindness from decreased blood
supply via the ophthalamic artery.
Accidents (such as chemical burns or sports injuries)
Trachoma.
Vitamin A deficiency.
Complications of eye surgery.
congenital cataract
congenital glaucoma

6. India
2001-02 National survey on blindness
– Cataract 62.6%
– Uncorrected Refractive error 19.7%
– Glaucoma 5.8%
– Posterior segment pathology 4.7%
– Corneal opacity 0.9%
– Other causes 6.2%

7. TYPES OF BLINDNESS
1. Partial Blindness - means very limited vision.
2.Complete Blindness- It means you cannot see
anything and do not see light.
3.Color blindness– difficulty to distinguish green and red
4. Night blindness – difficulty to see objects in dark
5. Snow blindness – temporary impairment in vision due
to excessive exposure to uv.
6. Legal blindness – central vision 20/200
7. Temporary blindness – vision loss shorter period
8. Permanent blindness – vision loss for life time
9. Unilateral blindness – loss of vision in one eye
10. Bilateral blindness – loss of vision in both eye

8. SIGNS & SYMPTOMS
• Seeing only shadows
• Poor night vision
• Tunnel vision- a vision defect where objects cannot be
seen unless they are near the center of the visual field.
• Cloudy vision

9. DIAGNOSTIC EVALUATION
• History collection
• Physical examination
• Visual acuity testing
• Ophthalmoscopy

10. MANAGEMENT
In some cases of vision impairment, one or more of the
following may help restore vision:
 Eyeglasses
 Contact lenses
 Surgery
 Medication
 If you experience partial blindness that can’t be
corrected, doctor will provide guidance on how to
function with limited vision.
For example, you can use a magnifying glass to read,
increase the text size on your computer, and use audio
clocks and audio books.

11. CONT…
Complete blindness requires approaching life in a new way
and learning new skills.
 For example, you may need to learn how to:
 Read Braille- a system of writing for the blind that uses
characters made up of raised dots.
 Use a guide dog
 Organize your home so you can easily find things and stay
safe
Fold money in distinct ways to distinguish bill amounts
You can also consider getting some adaptive products, like a
specialized Smartphone, color identifier, and accessible
cookware.
There’s even adaptive sporting equipment, like sensory
soccer balls- blind or vision impaired with game balls with
beepers and/or bells to allow auditory tracking.

12. PREVENTION
To detect eye diseases and help prevent vision loss, get regular
eye examinations.
 If you receive a diagnosis of certain eye conditions, such as
glaucoma, treatment with medication can help prevent
blindness.
 To help prevent vision loss, the American Optometric
Association recommends that have child’s eyes examined:
 at 6 months of age
 at 3 years of age
 every year between 6 and 17 years old
 If you notice symptoms of vision loss between routine visits,
make an appointment with their eye doctor immediately.

13. THANK YOU