Cataract can be identified as development of clouding in the crystalline lens of the eye, which lies behind the iris and the pupil. Cataracts are made from a protein, altered from its natural state and distorted, eventually obstructing the entry of required light into the retina of the eye. They, more often than not, don't cause any problems in the initial years of their development. However, as they mature, the cloudiness on the lens increases and significant loss in eyesight results, leading to blinding in certain cases. Occasionally, cataracts may also develop rapidly. They affect both the eyes in most of the cases, but can develop rapidly in any one of the affected eyes.
Causes of Cataract
There can be a multitude of reasons for the development of cataract. The major ones have been listed below:
- Medical procedures undertaken to correct other vision problems, such as glaucoma, may result in secondary cataracts.
- Traumatic cataracts may develop from an injury caused to the eye-lens or the eye as a whole.
- Congenital cataracts are genetic in nature and found in babies. In some cases, they develop in childhood only.
- Radiation cataracts develop after excess sun exposure. Studies show that cosmic radiations also lead to the development of cataract.
- Researches have also shown that cataracts may develop due to long term use of certain steroids and also because of some lifestyle habits.
- Diabetes and regular smoking has also been identified as the reasons behind cataracts.
- Visual changes like blurred vision, difficulty with glare and dulled color vision.
- Cataract may make the sunlight or a lamp appear too glaring.
- Increased nearsightedness, accompanied by frequent changes in eyeglass prescription.
- Double vision is also experienced occasionally, in one eye.
- Some people also notice a phenomenon called 'second sight'. In this condition, the reading vision of the person improves due to increased nearsightedness, as a result of swelling of the cataract. However, as cataract worsens, this improved vision fades away.
Diagnosis & Treatment
A routine examination of the eye can detect early cataract development, even when one may not be experiencing cataract symptoms, like blurred vision. Clouding of the lens is not very common before the age of 40. Cataract surgery is to be considered only when the visual symptoms mark their appearance. For early cataract changes, vision can be simply improved by changing the patient's eyeglass prescription. Strong bifocals, magnification, appropriate lighting or other visual aids may also be used.
Cataracts can, eventually, reach a stage where surgery is the only effective intervention in the seriously impaired vision condition. The two types of eye surgery performed to remove cataracts are extra-capsular and intra-capsular surgeries. Extra-capsular surgery removes the lens, but leaves majority of the lens capsule intact, while the entire lens, including the lens capsule, is removed in intra-capsular surgery. However, intra-capsular surgery is rarely performed in modern medical practice. In both of the above mentioned surgeries, a plastic lens is used to replace the cataract-affected lens, which stays in the eye permanently.