Overview
A cataract is clouding of the eye's natural lens, blurring vision like looking through a fogged window. It develops slowly, usually with age, and is the most common cause of treatable blindness globally. A short, safe operation replaces the cloudy lens and restores sight — no drops or drugs can clear an established cataract.
Symptoms
- Gradually blurring or dimming vision
- Glare and difficulty with bright sunlight or night driving
- Colours appearing faded or yellowed
- Frequent changes in glasses prescription
- A whitish appearance in the pupil (advanced)
- Double vision in one eye
Causes & risk factors
- Ageing of the lens
- Diabetes
- Long-term sunlight exposure
- Eye injury or inflammation
- Smoking and long-term steroid use
Treatment & self-care
Early on, updated glasses and good lighting help; when vision interferes with daily life, a surgeon removes the cloudy lens and implants a clear artificial one — typically a day procedure with quick recovery. Surgery is the only effective treatment. Untreated advanced cataract in children needs especially urgent referral.
See a doctor urgently if
- Blurring that interferes with work, reading or recognising faces
- A white spot visible in the pupil — urgently in a child
- Sudden vision change, pain or redness
- Diabetes with any visual blurring