Cataract is currently the leading cause of blindness worldwide. Of the 28 million (visual acuity less than 20/400), an estimated 17 million cases are due to age-related 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.
Reasons for Cataracts
- Intense UV sunlight exposure
- Malnutrition: A large number of children develop them because of nutrition deficiency and/or low antioxidants in their diet. People who tend to eat just rice and barley and have very intense UV sunlight exposure develop blinding cataracts at a much higher prevalence.
Barriers to Cataract Care
- Unaware of diagnosis or possibility of surgery
- False beliefs about surgery and/or outcome
- Economic constraints (cost of surgery, transportation, loss of work for patient/caregiver, living expenses of caregiver)
- Patient’s own beliefs/attitudes/education (fear, family pressure, fatalities or religious attitude)
- Access to eye care services
Source: "Fighting Global Blindness"