Cataract Causes
Most people develop some lens clouding after age 60 years. About 50% of Americans aged 65-74 years have cataracts, as do about 70% of those 75 years or older. Most people develop the problem in both eyes, although clouding in one eye may be worse than in the other eye. Many people do not know they have cataracts.
In many cases, the cause of cataracts is unknown. Factors that may contribute to cataract development include diabetes, long-term use of corticosteroids, and other inflammatory and metabolic disorders. Other contributory factors include the following:
Age related: Most cataracts are related to aging.
Childhood: Some cataracts develop at birth or in childhood, often in both eyes. These may or may not affect vision.
Hereditary: A family may have a history of developing cataracts.
During development: A mother may transmit cataracts to her baby during pregnancy if the mother has an infection, such as rubella (German measles).
Secondary cataract: Cataracts may be linked to certain other health problems, such as diabetes or steroid use.
Traumatic: Cataracts may follow an injury to the eye, either quickly or years later.
Other causes: Cataracts may follow radiation exposure and excessive exposure to UV light (sunlight), smoke, or alcohol.
