Causes of Cataracts
Causes of cataracts are diverse and range from age-related changes to environmental and medical influences. The most frequent causes of cataracts include natural ageing, trauma, underlying health conditions, medication side effects, and lifestyle factors.
The primary and most common cause is ageing. As people get older, the proteins in the lens naturally begin to break down and clump together. These changes gradually lead to clouding of the lens — the hallmark of age-related cataracts. Most individuals over the age of 60 will show some signs of lens clouding, even if vision isn’t yet affected.
Eye injuries can also lead to traumatic cataracts. A direct blow or penetrating injury may damage the lens, and sometimes, cataracts appear years after the incident. Inflammatory eye diseases such as uveitis can also trigger cataract formation by altering the internal eye environment.
Certain systemic illnesses significantly increase the risk. For example, people with diabetes are more likely to develop cataracts at a younger age. High blood sugar levels cause chemical changes in the eye that accelerate lens clouding.
Long-term use of corticosteroids, especially in oral or eye-drop form, is a known risk factor for posterior subcapsular cataracts — a type that forms at the back of the lens and can progress rapidly. Other medications, including some used in cancer treatment or for treating autoimmune diseases, can also affect the lens.
Exposure to ultraviolet (UV) light over many years is another major contributor. People who spend a lot of time outdoors without wearing UV-protective eyewear are more susceptible. Similarly, smoking and excessive alcohol consumption increase oxidative stress on the eye and are linked to earlier cataract development.
Causes of Cataracts
Some people are born with congenital cataracts, usually due to genetic conditions or infections passed from mother to baby during pregnancy. These may affect vision immediately or progress over time.
By understanding the various causes of cataracts, individuals can take preventive steps — such as protecting their eyes from sunlight, managing chronic illnesses, and avoiding smoking — to reduce the risk of early onset or progression.
[Next: Symptoms of Cataracts →]
