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In the least-developed countries, 50 percent of avoidable blindness is caused by cataracts.

World Blindness Overview

While many public health problems cannot be prevented, one striking exception is cataracts.

A blind man guided by a stick in Ghana.

Definition of Blindness

Blindness: The condition of lacking visual perception due to physiological or neurological factors. Every country in the world differs in its definition of “legal blindness.” In North America and most of Europe, legal blindness is defined as visual acuity (vision) of 20/200 (6/60) or less in the better eye with best correction possible. This means that a legally blind individual would have to stand 20 feet (6.1 m) from an object to see it—with vision correction—with the same degree of clarity as a normally sighted person could from 200 feet (61 m).

Causes of Blindness

In the least-developed countries, and in particular Sub-Saharan Africa, the causes of avoidable blindness are primarily, cataract (50%), glaucoma (15%), corneal opacities (10%), trachoma (6.8%), childhood blindness (5.3%) and onchocerciasis (4%). Source: World Health Organization

Blindness is most prevalent in developing countries where malnutrition, inadequate health and education services, poor water quality and a lack of sanitation leads to a high incidence of eye disease.

Geographical Distribution of Global Blindness

Global blindness
Source: Vision 2020

A person is “functionally blind," as defined by the World Health Organization, when he or she is unable to perform the tasks of daily living that are needed to survive. Blindness defined for international health purposes is when an individual cannot count fingers at 10 feet. Blindness for the destitute is an almost certain death sentence.

Blindness is particularly devastating in the developing world where it has a profound impact on the quality of life for the blind person and his or her community.

Life expectancy of the blind is usually less than half that of someone with eyesight the same age. The desperateness of this situation is augmented by the fact that a blind person is unable to contribute to the family income. Not only does blindness mean a father is unable to work, or a mother cannot collect water or go to market, but someone with eyesight must care for him or her. Effectively two income producing individuals are lost. This creates a devastating economic impact on the family and the community. Restored eyesight allows the individual to return to a normal life of work and a traditional role in the family.

According to the World Health Organization, "a conservative estimate of the annual direct economic productivity loss due to blindness and low vision in sub-Saharan Africa is US$1,830 million in 2000. Without concerted international action, it is expected to rise to $4,374 million per year by 2020, the equivalent of 0.50 percent of GDP for the region."

Despite the hard work of HCP, Tilganga and many others in eliminating unnecessary blindness, the backlog of blind people in the developing world continues to grow.

Can You Imagine Being Blind in the Developing World?

A blind woman in Nepal is carried down a path by a family member.

In the developing world, a blind person is most often found living in a subsistence community or a squalid slum. In rural areas, a family member who becomes blind changes from being a contributor to a family burden. A husband cannot work in the fields, a mother cannot walk over rough terrain to take her goods to market, or collect water, and a child cannot attend school (if that is a possibility.)

Not only can this blind individual no longer work but extra care is required from a family member who would otherwise be making a living or contributing to the community work force. The physical and emotional toll impacts not just the individual and family but the social and economic fabric of the communities and everyone’s existence. Sudden blindness of one individual in a family can become the tipping point for survival when they are impoverished to begin with.

When someone becomes blind in the developing world:

  • 90% of these individuals can no longer work.
  • Life expectancy drops down to 1/3 that of a matched peer, in age and health.
  • 50% of the blind report a loss of social standing and decision-making authority.
  • 80% of all women note a loss of authority within their families. (Javitt, Int. Congr. Opthalmol., 1983).

The blind person is totally dependent. If the family cannot afford the time for someone to help their blind family member, the individual is totally neglected and often left alone in a corner for the day.

This is reversible.

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World Blindness

  • More than 180 million people are visually disabled throughout the world.
  • Of this group, 45 million people are completely blind.
  • And of this group of 45 million blind people, 90% of them live in the developing world.

“Fighting Global Blindness: Improving World Vision Through Cataract Elimination”

Global blindness

Written by HCP Co-Directors Dr. Sanduk Ruit and Dr. Geoff Tabin and HCP friend Dr. Charles Wykoff, “Fighting Global Blindness: Improving World Vision Through Cataract Elimination” tackles the topic of fighting global blindness. Learn more.