Cataracts form when the clear lens inside your eye becomes cloudy, which blocks or distorts light passing through to the retina, causing vision to blur. The primary cause of cataracts is **aging**. As you get older, the proteins in the lens start to break down and clump together, creating cloudy areas that gradually worsen over time. This process usually begins in middle age but often doesn’t affect vision noticeably until later in life.
Beyond aging, several other factors contribute to cataract formation. **Genetics** plays a role, meaning if close family members have had cataracts, your risk increases. Certain **chronic diseases** like diabetes and high blood pressure can accelerate cataract development by damaging the lens through changes in blood sugar and circulation. Prolonged **exposure to ultraviolet (UV) light** from the sun also harms the lens proteins, speeding up clouding. This is why people who spend a lot of time outdoors without eye protection are more prone to cataracts.
Lifestyle choices have a significant impact as well. **Smoking** introduces harmful chemicals that damage the eye’s lens, increasing cataract risk. Excessive **alcohol consumption** can similarly contribute to lens damage. Long-term use of certain medications, especially **steroids**, is another known cause because steroids can alter the metabolism of lens cells, leading to cloudiness. Eye injuries or trauma can also trigger cataracts by physically damaging the lens or causing inflammation.
There are different types of cataracts depending on where the cloudiness forms in the lens. The most common is the **nuclear cataract**, which develops in the center of the lens and is strongly linked to aging. **Cortical cataracts** form on the outer edges of the lens and look like spokes extending inward. **Posterior subcapsular cataracts** occur at the back of the lens and tend to affect reading vision and cause glare more than other types.
Cataracts develop slowly and painlessly. Early on, vision changes might be subtle, such as slight blurriness, increased sensitivity to glare, or colors appearing faded or yellowed. Sometimes, people notice frequent changes in their eyeglass prescription. As cataracts progress, vision becomes more clouded, making everyday activities like reading, driving, or recognizing faces difficult. In advanced stages, the lens can become so opaque that it blocks almost all light, leading to severe vision loss or blindness.
While cataracts are mostly age-related, they can also occur in babies (congenital cataracts) or after eye surgery or inflammation. Certain health conditions like obesity and systemic diseases can increase the risk or speed up cataract formation. The combination of aging, environmental exposure, health status, and lifestyle choices all interact to determine how and when cataracts develop.
The only effective treatment for cataracts is surgical removal of the cloudy lens, which is then replaced with a clear artificial lens implant. This restores vision by allowing light to pass through unobstructed again. Before surgery becomes necessary, vision changes caused by cataracts can sometimes be managed temporarily with new glasses or brighter lighting, but these do not stop cataracts from progressing.
In essence, cataracts result from the natural aging process of the eye’s lens combined with various risk factors like genetics, chronic diseases, UV exposure, lifestyle habits, medications, and injuries. Understanding these causes helps in early detection and timely treatment to maintain good vision throughout life.
