Cataract (a waterfall in Latin)
The lens helps us to focus the picture the eye received. It is normally perfectly transparent but becomes less so with age. An early cataract may cause the patient to see haloes around lamps or cause glare, particularly when driving, but as the opacity progresses, the vision becomes blurred, causing difficulty reading and in day to day visual tasks. An advanced cataract may make the pupil appear white.
Cataract is the most common cause of blindness in developing countries.
A cataract usually appears after the age of 65, but is occasionally seen at an earlier age. A cataract in young people is sometimes associated with a systemic condition. A particular type of cataract may be present at birth or soon after.
When the cataract reaches the stage when it disturbs the vision it is removed by surgery. There is no other effective treatment. Eye drops and ointment are installed to anesthetize the eye. The opaque lens is removed through a very small incision using an ultrasound probe and suction – a process called phacoemulsification – and is replaced by a tiny artificial (intraocular) lens. The entire procedure takes about 20 minutes.
The vision is usually satisfactory the day after surgery, allowing the patient to return to almost full activity, and continues to improve over a period of 2-3 weeks. Most patient still need spectacles following surgery, mainly for reading.