A healthy lens is a clear structure, allowing light to enter the eye. It focuses that light onto the retina, which enables clear vision. Cataracts are caused by proteins that clump together on the lens, making it cloudy. These protein aggregates get larger over time, and may also cause the lens to discolor. A cloudy and discolored lens will not filter light appropriately and therefore cause visual disturbances. The most frequent cause of this is normal aging, and most cataracts will occur in people over the age of 60. Other contributing factors include genetics, smoking, diabetes, and sun damage. A severe trauma to the eye can also cause a cataract to develop.[1]
What causes cataracts?
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•Last Updated: May 16, 2025
Cataracts are caused by proteins that clump together in the lens, which leads to cloudiness and discoloration that disrupts light filtration and vision. The primary cause is aging, particularly in people over age 60, and additional risk factors include genetics, smoking, diabetes, sun damage, and eye trauma.