Cataract Causes & Risks

Causes

The lens of the eye is made of mostly water and protein. The protein is arranged in a way that keeps the lens clear and lets light pass through it. A cataract forms when some of the protein clumps together and starts to cloud an area of the lens. A cataract won't spread from one eye to the other, although most people develop cataracts in both eyes at a similar times.

There are several causes of cataracts, including:

Aging (the most common cause)
Smoking
Diabetes
Infection
Injury
Exposure to radiation
Taking adrenal cortical hormones for a long time
Excessive exposure to sunlight
Birth defect

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors include:

Age
Exposure to UV-B radiation from sunlight
Family members with cataracts
Diabetes
Trauma
Smoking

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition. Copyright © 2025 EBSCO Publishing All rights reserved.