CureBlindness | Cause


Eye care is one of the greatest public health challenges for the 21st century. Of the more than 36 million people worldwide suffering from unnecessary blindness, more than half are due to cataract – which can be surgically treated. Most of these people live in low to middle income countries, where poor nutrition and limited access to eye care can mean a life limited by needless blindness. Numerous studies have shown that sight restoration with cataract surgery is among the most cost-effective interventions in health care.

The Cause

Over One Million Cataract Eye Surgeries Makes A Difference In The World

Many serious public health problems cannot be easily cured. One striking exception is cataract-induced blindness.

Since 1995, the Himalayan Cataract Project and its global partners have performed more than one million ophthalmic surgeries in low to middle income countries through improvised mobile eye clinics and high-volume cataract campaigns. The life-changing, manual, sutureless procedures can be completed in less than 10 minutes at a material cost of just $25 apiece. Some 16 million needlessly-blind cataract patients still await care, most of them with no place to turn.

Cataract surgery is considered one of the most cost-effective medical interventions in the world.

Definition of Blindness

In terms of public health, blindness is defined as being unable to see the big "E" on the eye chart in either eye and most blind persons are unable to detect more than a shadow when a hand passes in front of their face. A person is functionally blind, according to the World Health Organization, when he or she is unable to perform the basic tasks of daily living.

Blindness is particularly devastating in low to middle income countries, where it has a profound impact on the quality of life for the blind person and his or her community. Blindness takes an able-bodied person out of the workforce, or a child out of school to lead a parent around by a stick. Spouses are often required to become full-time caregivers, and two income-producing individuals in a family are effectively lost. When a family is impoverished to begin with, the blindness of a single family member can become the tipping point for survival. For the destitute, blindness is often a death sentence.

Causes of Blindness

Blindness is most prevalent in low to middle income countries where malnutrition, inadequate health and education services, poor water quality, and a lack of sanitation lead to a high incidence of eye disease. Fully 90 percent of the world’s visually impaired live in low-income settings.

In the least-developed countries, and in particular Sub-Saharan Africa, cataracts are responsible for half of all avoidable blindness. Other causes include glaucoma (15%), corneal opacities (10%), trachoma (6.8%), childhood blindness (5.3%), and onchocerciasis (4%). A simple, low-cost, one-time procedure can restore full sight to patients with cataracts — but in too many places those procedures are not yet available.

(Source: World Health Organization)

geographical distribution of global blindness

In low-to-middle income countries, 50 percent of avoidable blindness is caused by cataracts.

What is a Cataract?

A cataract is a cloudy or opaque area in the normally transparent lens of the eye. A cataract occurs when clumping of cells or protein causes a cloudy or opaque area in the transparent lens which, as it thickens, obstructs entering light.

As the opacity thickens, it prevents light rays from passing through the lens and focusing on the retina, the light sensitive tissue lining the back of the eye. Early changes or opacities in the lens may not disturb vision; however, as the lens continues to change, several specific symptoms including blurred vision; sensitivity to light and glare; increased nearsightedness; or distorted images in either eye, may develop.

The lens is located behind the iris, the colored portion of the eye, and the pupil, the dark center of the eye. Tiny ligaments, called zonules, support the lens capsule within the eye.

The lens has three parts, the capsule, the nucleus, and the cortex. The outer membrane, or capsule, surrounds the cortex which in turn surrounds the center or nucleus of the lens. If you imagine the lens as a piece of fruit, the capsule is the skin, the cortex is the fleshy fruit, and the nucleus is the pit.

Cataract surgeries are performed by making tiny incisions on the eye through which the cataract is removed and a new lens is inserted. The new lens that is implanted is an intraocular lens – a highly specialized clear plastic substitute.