Cataracts
A cataract is a clouding of the eye's normally clear lens, which sits behind the pupil and helps focus light onto the retina. As the lens becomes cloudy, vision turns blurry, dim, or hazy. Cataracts usually develop slowly with age and can affect one or both eyes.
Overview
What are cataracts?
A cataract is a cloudy area that forms in the lens of the eye, the clear part behind the pupil that focuses light onto the retina. As proteins in the lens change with time, it becomes less transparent, so light cannot pass through clearly. This makes vision blurry, faded, or dim, and it usually develops slowly over months or years.
How common are cataracts and who do they affect?
Cataracts are very common and are one of the leading causes of reduced vision worldwide, especially in older adults. Most people who develop them are over the age of 60, and the risk rises steadily with age. Cataracts can affect one or both eyes, though they often progress at different rates in each eye.
Symptoms and Causes
What are the symptoms of cataracts?
Cataracts usually cause slowly worsening, painless changes in sight. Common symptoms include blurred or cloudy vision, colours looking faded or yellowed, difficulty seeing in dim light, and increased sensitivity to glare from lights or sunlight. Some people notice halos around lights, double vision in one eye, or that they need brighter light for reading.
What causes cataracts and who is at risk?
Most cataracts form as a natural part of ageing, when the lens gradually changes and clouds. Other factors can raise the risk, including diabetes, long-term use of certain medicines such as steroids, previous eye injury or surgery, and heavy exposure to ultraviolet light. Smoking and a family history of cataracts may also increase the chance of developing them.
Diagnosis and Tests
How are cataracts diagnosed?
An eye specialist diagnoses cataracts during a routine eye examination. They check how well you can see using a vision chart and use eye drops to widen the pupil so the lens can be viewed closely with a special microscope. This lets them see the clouding, judge how advanced it is, and rule out other causes of blurred vision.
Management and Treatment
How are cataracts treated or managed?
In the early stages, stronger glasses, brighter lighting, and reducing glare may help enough that no other treatment is needed. When a cataract begins to interfere with daily life, surgery to remove the cloudy lens and replace it with a clear artificial lens is a common and well-established option. Your eye specialist can explain the choices and the right timing for you.
Prevention
Can cataracts be prevented or their risk reduced?
There is no guaranteed way to prevent cataracts, as ageing is the main cause, but some steps may help protect your eyes. Wearing sunglasses that block ultraviolet light, not smoking, managing conditions such as diabetes, and attending regular eye check-ups can all support eye health. A balanced diet rich in fruit and vegetables is also generally good for your eyes.
Additional Common Questions
Are cataracts a normal part of getting older?
Yes. Most cataracts develop gradually as part of the natural ageing of the eye's lens. They are very common in older adults, and developing one does not mean anything has gone wrong.
Will a cataract make me go blind?
A cataract can seriously blur vision if left untreated, but it is generally not a cause of permanent blindness in places where treatment is available. Vision can usually be restored once the cataract is removed.
Do cataracts come back after they are treated?
The cataract itself does not return, because the cloudy lens is replaced. Some people later notice clouding behind the new lens, which can be treated separately, so it is worth mentioning any new blurring to your eye specialist.
This health topic is for general information and is not a substitute for professional medical advice. Always consult a qualified clinician about your individual situation. See our medical disclaimer.