What is cataract?

Cataract occurs when there is a clouding of the lens in the eye and is most often associated with aging. More than half of all Americans have a cataract or have had cataract surgery by age 80 years, according to the National Eye Institute of the National Institutes of Health.

Normally, light passes through the eye’s transparent lens to the retina where light is changed into nerve signals sent to the brain. However, with a cataract, images are blurred from a cloudy lens.

The eye lens is mainly composed of water and protein. As people age, the protein can sometimes clump together and cloud the lens, resulting in a cataract. Diabetes, smoking and prolonged exposure to sunlight have been linked with cataract. The normal wear and tear of the lens over time is also a cause, according to the National Eye Institute.

While most cataracts are associated with aging, there are other types that may result from surgery, eye injury or exposure to radiation. In addition, infants may be born with cataracts or develop them during childhood. These types are called secondary cataract, traumatic cataract, radiation cataract and congenital cataract.

Some cataracts are small, but they can grow slowly and become larger in size. Others change the eye lens to a yellow/brown color, resulting in brownish tint vision. Although the sharpness of vision is not affected by this tinting, as time passes, the tinting may increase, making it difficult to read or perform other activities.

The development of cataract may be delayed by wearing sunglasses and a brimmed hat to block UV light, stopping smoking, and receiving proper nutrition.

The National Eye Institute recommends having a comprehensive eye exam once every 2 years because “early treatment for many eye diseases may save your sight.” Comprehensive eye exams include a visual acuity test, dilated eye exam and tonometry.

Treatment for early cataract may include new eyeglasses, magnifying lenses, anti-glare sunglasses or brighter lighting. However, the only effective treatment available if these measures do not help is surgery to remove the cloudy lens and replacing it with an artificial lens, known as an intraocular lens. The types of surgeries available are phacoemulsification or extracapsular surgery. For those who cannot have an intraocular lens implanted due to another eye disease or who experience problems during surgery, either soft contact lenses or high-magnification eyeglasses are alternatives.

Additional information may be found at these websites:

https://www.nei.nih.gov/health/cataract/cataract_facts

http://www.hopkinsmedicine.org/wilmer/conditions/cataracts_faq.html

http://www.kellogg.umich.edu/patientcare/conditions/cataract.html