Normal Eye |
The natural lens inside our eyes is transparent. But it loses its transparency with age. Cataract is an opacity in this natural lens. The lens works with the transparent cornea, which covers the eye's surface, to focus light on the retina at the back of the eye. When the lens becomes cloudy, or cataractous, light cannot pass to the retina properly, and vision is blurred and decreased.
The most common type of cataract is that caused by old age. So in the strictest sense of the word, this type of cataract is not a disease. The other causes of cataract include injury, eye inflammation, systemic diseases like diabetes and drugs like steroids. Here is a more complete list. |
What are the symptoms of cataract ?
Mature Cataract |
Cataract is a very slowly progressive condition. The earliest symptoms are glare which is manifested by marked decrease in vision in the presence of bright light. This makes driving at night very difficult. Other symptoms include spreading of light, frequent change in refraction requiring frequent change of glasses. As the cataract develops there is fall in vision which cannot be corrected by glasses. |
When is the right time to operate a cataract ?
Central Cataract |
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Modern day cataract surgery techniques have changed the approach to cataracts. In the past patients were advised to wait for the cataract to mature ( or "ripen"). This made the job of removing the cataract easier for the surgeon. However with the advent of modern microscopes the cataract is better dealt with when immature. Also phacoemulsification is easier done in an immature ("unripe") cataract. More the cataract matures the harder the lens and more the effort to emulsify the lens.
So unless specified by your doctor the right time to operate is when the visual impairment hinders normal day to day activities.
Additional problems in a mature cataract.
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What are the types of surgery available ?
Cortical Cataract |
(a) Intracapsular cataract surgery: In this type the entire cataract is removed along with it's covering capsule. This type is not very popular nowadays because insertion of the IOL is difficult in these cases. Also the risk of vitreous loss is much more. |