Cataracts
How common are cataracts?
Approximately 48% of all visual impairments worldwide are due to cataracts (source World Health Organisation estimates of 2002).
What causes cataracts?
Cataracts form for a variety of reasons, including long-term ultraviolet exposure, secondary effects of diseases such as diabetes, or simply due to advanced age; they are usually a result of denaturation of lens proteins. Genetic factors are often a cause of congenital cataracts and positive family history may also play a role in predisposing someone to cataracts at an earlier age, a phenomenon of "anticipation" in pre-senile cataracts. Cataracts can also be produced by eye injury or physical trauma. A study among Icelandair pilots showed commercial airline pilots as three times as likely to develop cataracts as people with non-flying jobs. This is thought to be caused by radiation coming from outer space. Cataracts are also unusually common in persons exposed to infrared radiation like the glassblowers who suffer from "exfoliation syndrome". Exposure to microwave radiation can cause cataracts.
Cataracts may be partial or complete, stationary or progressive, hard or soft.
Are cataracts curable?
The most effective and common treatment is to surgically remove the cloudy lens. There are two types of surgery that can be used to remove cataracts, extra-capsular and intra-capsular surgery. Extra-capsular surgery consists of removing the lens but leaving the majority of the lens capsule intact. High frequency sound waves (phacoemulsification) are sometimes used to break up the lens before extraction. Intra-capsular surgery involves removing the entire lens of the eye, including the lens capsule, but it is rarely performed in modern practice. In either extra-capsular surgery or intra-capsular surgery, the cataractous lens is removed & replaced with a plastic lens (an intraocular lens implant) which remains permanently in the eye.
What is it like to see with a cataract?
The images below give a very rough idea of what it is like to see with a cataract.
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| Normal Sight | Same image seen with cataract |
Suitable reading aids for people with cataracts
You can find our range of suitable electronic magnifiers here
Some people's eye conditions may make the use of an electronic magnifier difficult. This is where our range of easy to use text to speech reading machines may be more suitable.
Acknowledgements: Wikipedia: Cataracts
