VISUAL IMPAIRMENT – FACTS
WHO statistics has revealed the following interesting and surprising facts on Visual Impairment
● 285 million people are estimated to be visually impaired worldwide of which 39 million people are blind and 246 million people have low vision.
● About 90% of the world’s visually impaired live in low-income settings.
● 82% of people suffering from blindness are aged 50 years and above.
Global estimates have revealed:
● Visual impairment due to infectious diseases has reduced in the last 20 years
● Uncorrected refractive errors are the main cause of moderate to severe visual impairment
● Cataracts are the main cause of blindness in developing countries
● 80% of all visual impairment can be prevented or cured.
Since visual impairment has such great influence on our well being, we need to understand the causes of visual impairment
Worldwide the major causes of visual impairment are:
● Uncorrected refractive errors (myopia, hyperopia or astigmatism) – 43 %
● Un-operated cataract – 33%
● Glaucoma – 2%.
What is visual impairment?
To understand Visual impairment first let us understand what is Normal vision
Normal vision – person with visual acuity of 6/6 or 20/20 is considered to be normal vision,
Visual Impairment is also known as Vision loss or Blindness which refers to a condition wherein a person suffers from any of the following
a. Total absence of sight.
b. Visual acuity not exceeding 6/60 or 20/200 in the better eye with best correcting lenses
c. Limitation of field of vision subtending an angle of 20 degree or worse
In India a person with a VA < 6/60 is legally blind
Person with low vision means a person with impairment of vision of less than 6/18 to 6/60 with best correction in the better eye or impairment of field in any one of the following categories:
a. Reduction of fields less than 50 degrees
b. Heminaopia with macular involvement
c. Altitudinal defect involving lower fields
With these interesting facts let us understand the measures to improve our vision and tips to avoid or delay visual impairment .