Cataract
What is Cataract?
Normally, the lens of the eye is clear and allows light rays to pass through easily.When a cataract develops, the lens becomes cloudy and opaque. The light rays no longer pass through the lens easily, so the patient cannot see clearly.
- Cataract is not a new growth or a film over the eye. In most cases, it is just part of the aging process.
- It is not contagious
Types Of Cataract
There are many types of cataracts.
A change in the chemical composition of the lens causes most cataracts. The following are the various types of cataracts.
Senile Cataract
This is the most common type of cataract, comprising 80 percent of the total cataracts. It occurs in patients above the age of 50.
Congenital Cataract
Cataracts in children are rare. They can be caused by infection of the mother during pregnancy, or they may be hereditary.
Traumatic Cataract
Eye injuries may cause cataracts in patients of any age.
Secondary Cataract
Eye diseases, like glaucoma, iritis, eye tumours, and diabetes may cause cataracts.
Drug-induced Cataract
Prolonged treatment with steroid drugs, either for local (e.g., allergic conjunctivitis) or systemic diseases (e.g., asthma) may lead to cataract formation.
Symptoms of Cataract
Cataract formation is not associated with "signals" such as pain, redness or tearing. The common symptoms are:
(i)Blurring or dimness of vision |
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(ii)Feeling of a film over the eyes |
(iii)Sensitivity to light and glare |
Treatment :
Cataract cannot be cured by medicines or spectacles. Removal of the clouded lens through surgery is the only treatment.
Types of Cataract Removal:
Routine method (old method)
After administering a local anaesthesia, a 10 mm incision is made in the eye. The cataract lens is removed and it may be replaced by an Aphakic glass. The incision is then closed with sutures. After the surgery, glasses with high power called ophakic spectacles are prescribed to the operated person.
Disadvantages:
These ophakic glasses are heavy, images seen are larger than they normally appear to be, and the field of vision is restricted.
