What causes cataracts in the eyes and how to prevent them?

06/03/2025

Cataracts are one of the most common eye conditions, particularly among older adults. However, many people wonder: Why do cataracts develop? There are various risk factors that can accelerate their onset and impact eye health. In this article, we explore the main causes of cataracts, the factors that increase their risk, and the best strategies for prevention.

Main causes of cataracts

Ageing: the most common cause

Ageing is the primary reason for the development of cataracts. Over time, the proteins in the eye's lens degrade and clump together, leading to the lens becoming cloudy. This is a natural and progressive process, although there are ways to slow it down.

Genetic factors: hereditary cataracts

Hereditary cataracts can appear at a younger age than age-related cataracts. If there is a history of early-onset cataracts in your family, you may have a higher predisposition to developing them.

Prolonged sun exposure

Ultraviolet (UV) light from the sun can damage the lens and accelerate the formation of cataracts, especially when combined with malnutrition, as seen in developing countries. Wearing sunglasses with UV protection can help reduce this risk.

Cataracts due to diabetes and other diseases

People with diabetes are at a higher risk of developing cataracts due to high blood sugar levels, which affect the lens. Other autoimmune diseases, such as lupus or rheumatoid arthritis, can also contribute to their onset, as can any condition that disrupts the eye's metabolism.

Prolonged use of certain medications

Long-term use of corticosteroids and other medications can promote the development of cataracts. It is essential to consult an ophthalmologist if you take these types of drugs regularly.

Eye trauma

Blows or injuries to the eyes can lead to traumatic cataracts. Although symptoms may take years to appear, it is crucial to seek ophthalmic care following any eye injury or trauma.

Lifestyle factors: smoking and alcohol

Smoking and excessive alcohol consumption increase the risk of developing cataracts, as they produce toxic substances that damage eye cells. Adopting a healthy lifestyle can help prevent them.

How to prevent cataracts?

While some causes of cataracts are unavoidable, there are ways to reduce the risk and delay their onset:

• Protect your eyes from the sun by wearing sunglasses with a UV filter.
• Maintain a balanced diet rich in antioxidants, vitamins C and E.
• Manage conditions such as diabetes to prevent early cataracts.
• Avoid smoking and excessive alcohol consumption to maintain good eye health.
• Have regular eye check-ups to detect any signs of cataracts.

If you have already developed cataracts, surgery is the only effective treatment to restore vision. Fortunately, cataract surgery is a simple, safe, and highly successful procedure. Consulting an ophthalmologist will help determine the best time for surgery and improve your quality of life.

Dr Elena Barraquer, ophthalmologist at the Barraquer Ophthalmology Centre