A cataract is a clouding of part of the eye known as the lens, which is normally clear.The lens is a structure that lies immediately behind the pupil, and changes shape to enable the eye to focus at different distances. The picture below shows how an eye with advanced cataract appears in comparison to a normal eye.
Vision becomes increasingly blurred and misty as the cataract develops. It causes glare and dazzle from bright light sources – sunlight and car headlights can be particularly problematic. It can also cause ‘ghosting’ or ‘doubling’ of images.
Cataracts are most common in older age, and usually result from long-term exposure to the ultra-violet (UV) radiation in sunlight. In younger people they can also result from injury, certain types of medication, long-standing inflammation or illnesses such as diabetes. Usually both eyes are affected, although the cataract may be worse in one eye first.
Onset of cataract can lead to more frequent changes in spectacle prescription, which can help the vision to a certain extent. However, it won’t remove the cloudiness itself, and when the visual problems caused by the cataract become significant the only effective treatment is an operation.
Cataract surgery is usually carried out using local anaesthetic. The old cloudy lens is removed from the eye and an artificial lens is put in its place. The process doesn’t usually take more than about 30 minutes, and the patient is often allowed to go home on the same day. The eye will be re-assessed after a week or two to make sure it’s healing properly, and after 4-6 weeks an eye examination can take place to assess the need for spectacles.
Whilst all procedures carry a risk, in cataract surgery this risk is very small and the outcomes are usually very good indeed.
NB – The cataract infographic on the right side of this page is supplied courtesy of the Association of British Dispensing Opticians.
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