National Association for the Blind - Karnataka




It is estimated that out of the total world population, approximately 9 million are blind. Out of this India’s share is estimated at 4.5 million, i.e. 50% of the population. But except for their challenge of vision, a large number of the blind are able bodied men and women who, given the right opportunity, can make significant contributions to the society. But that would require sensitivity and understanding of facts on the part of the sighted and the larger society. So here are some quick facts.

In normal practice, a person who has normal vision is referred to as having central visual acuity of 6/6. By central visual acuity is meant the ability of the eye to perceive and discriminate the shape or form of object in direct line of vision. 6/6 implies that the person is able to perceive clearly at 6 meters what an average normal vision person perceive clearly at the same distance, i.e. 6 meters. If we say a person has central visual acuity of 6/18, it means that what object a person with normal vision perceives clearly at 18 meters, can be perceived clearly by this person (having visual acuity of 6/18) only by going nearer up to 6 meters. The testing of central visual acuity of a person is normally carried out by using suitable eye charts.


So we can now understand part of the formal definition of legal blindness as defined by the World Council for the Welfare of the Blind which is: ‘Central visual acuity of 6/60 or less in the better eye after correction.’ This means that what object a person with normal vision is able to perceive clearly at 60 meters, the blind or visually impaired can do so by getting as close as 6 metres to that object.


There is yet another state of blindness. This is related to Field Of Vision or Visual Field. A person may have good central visual acuity, i.e., more than 6/60 or even 6/6, but may suffer from narrow vision. That is, a normal person sighted person looking to his front, can perceive objects over an arc of 170 degrees from left to right. For a person to be declared legally blind on account of visual field, the widest diameter of the visual field must subtend an angle no greater than 20 degree at the eye. Another name for this defect is tunnel vision.

The principal causes of preventable visual impairment vary across regions. In developing countries like India, visual impairment associated with infections, nutritional deficiencies and trauma is much more common than it is in developed countries. Some of the eye conditions that contribute to visual impairment include:

  • Cataract - In India, Cataract is estimated to account for 55% of the blind population.
  • Trachoma – A contagious disease of the eye lid, it accounts for 5% of the population
  • Xerophthalmia- This is due to nutrition deficiency and is estimated to account for 2% of those afflicted with blindness.
  • Glaucoma – Accounts for about 0/5% of the incidences of blindness
  • Infection/injury/other causes - Infection accounts for about 15%, injuries 1.25% and other causes 21.25%. The other causes pertain to diabetic retinopathy, retinal detachment, retinal degeneration, ocular trauma and congenital and hereditary diseases.

Milestones in Mobility Training for the Visually Impaired

  • USA was the first country to start rehabilitation of blind war veterans, blind civilians and people with residual vision
  • The long cane techniques of mobility were developed by Dr Richard E Hoover at the US Army General Hospital, PA, USA during World War II.
  • In India, in the year 1967-68, the National Association for the Blind (NAB) workshop for the Blind appointed a mobility instructor for its Industrial Rehabilitation Unit .
  • In the World Council for the Welfare of the Blind Conference at New Delhi, the importance of orientation and mobility training was discussed in 1968 under the auspices of Blind Relief Association
  • For the first time, some of the Indian Instructors were sent to Malaysia to undergo training for Orientation and Mobility Instruction under the American Foundation for Overseas Blind, for East Regional office during 1968-1970.
  • The Year 1981 was ushered in a new era for mobility training in India. It was in this year that the NAB – Mumbai (the Bombay) launched a proposal to establish a mobility centre in India. The Mobility Training in Bangalore
  • The Mobility Training Centre in Bangalore at the time of its commencement in July 1982 was the only one of its kind in Asia solely engaged in conducting 6 weeks of residential mobility training programmes for the blind.
  • In 1982-83, NAB Karnataka Branch conducted the first Orientation and Mobility Officers’ course for 4 months as an Indo Australian project
  • A survey of ancient literature, historical records etc. reveal that blind mobility existed right through the ages. Ancient history give evidence of guide dogs and the use of familiar staff to help the blind as early as 1 st century AD
  • In 1930 the white cane was given official recognition in US when the city council in Illinois passed the first ordinance which gave blind pedestrians the right of way when carrying the white cane.
  • The white cane then came to be accepted across the world as a symbol of blindness.
  • The World White Cane Safety Day came to be observed on the 15th of October every year.
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