CAUSES OF PREVENTABLE BLINDNESS 

CATARACT

As per the above estimate, 80% of the blind are due to cataract; i.e. out of 12 million, nearly 9.6 million are due to this cause. There is a major National programme by the Government to restore sight of the cataract blind. Many NGO's are engaged in this task. On its part, NAB is also arranging cataract operations for children as well as adults. 
 

CORNEAL SCAR 

Adequate intake of Vitamin 'A' is essential for proper development of the retina as well as the superficial cell structures of the cornea, the skin, the lungs and the intestines. The earliest effect of Vitamin A deficiency involves the eye. It results in night blindness, dryness of the conjunctiva and cornea and ultimately m corneal ulceration, perforation and blindness. This is often aggravated by measles, diarrhoea and Conjunctivitis. 

It is essential to screen children upto age of 6 years and provide them half- yearly doses of Vitamin 'A' (200,000 IU) or alternatively fortified food or milk 
Adequate intake of Vitamin 'A' in childhood not only prevents loss of sight, it also contributes significantly to good health and reduction in mortality. In one country, proper administrative of Vitamm 'A' reduced mortality by 30% for children and 38% in case of pregnant mothers. 

It is also important to administrate Vitamin 'A' to lactating mothers. 

One of the causes for corneal scars is lack of Vitamin A. It is possible to undertake cornea transplant. It is possible to restore sight by transplantation of cornea or Keratoplasty.
 

GLAUCOMA

Glaucoma blindness occurs amongst people within the age group of 25-55 though it also affects to some extent people below and above this age group. In the case of Glaucoma very often the patient only becomes aware of his problem only when he loses vision significantly as in one type of Glaucoma (open angle) the patient does not experience pain. At this stage it is not possible to restore lost vision as Glaucoma causes permanent blindness and unlike cataract blindness, Glaucoma also occurs amongst younger group of people. It affects 2.3% of the population. 

The National Association for the Blind has established a Mobile Ophthalmic Unit which is fully air-conditioned and equipped with most modern equipment for the detection of Glaucoma. It is staffed by para-medical and medical staff comprising of optometrist, Ophthalmologist etc. 

The Mobile Opthalmic Unit operates in the slums of Bombay city and is equipped with the under mentioned diagnostic equipment such as Work Station, slit lamp with attached applanation tonometer, direct Ophthamoscope, Binocular Indirect ophthalmoscope, Schhotz Tonometer, Applanation tonometer etc. A full time Ophthalmic surgeon and optometrist and a driver have been engaged to provide totally free service. Those patients needing surgical intervention and referred for treatment to hospitals. 

The above note basically discusses the causes of blindness, the precautions that need to be undertaken to prevention visually impairment and also methods undertaken to restore sight in case of preventable blindness.