What are Cataracts?

A cataract is an opacity or cloudiness in the natural lens of the eye. It is still the leading cause of blindness worldwide and represents an important cause of visual impairment in the United Kingdom. The development of cataracts in the adult is related to ageing, sunlight exposure, smoking, poor nutrition, eye trauma, systemic diseases, and certain medications such as steroids. A single study has suggested that use of oral vitamin C may help delay the progression of cataracts.

Just as a smudged or dirty camera lens may spoil a photograph, opacity in the natural lens of the eye can result in a blurred image. Patients with cataracts usually complain of blurred vision either at distance, near, or both. This may interfere with tasks such as driving or reading. Other common complaints include glare, halos, and dimness of color vision.


How Are Cataracts Diagnosed?

A diagnosis of cataract can only be made by a thorough eye examination including slit lamp (microscope) evaluation. Other devices are sometimes used to determine if glare interferes with vision.

The progression of cataracts is highly variable, however, they will invariably worsen in severity. Changing glasses may sometimes be useful in improving vision as the cataract progresses, since cataracts may induce relative myopia (shortsightedness) . This is the answer as to why some patients with hypermetropia (longsightedness) will actually have better vision without glasses in the early stages of cataract development.

For most patients, however, changing glasses has minimal impact on overall visual quality. Besides changing glasses, the only other option for treatment of cataracts is cataract surgery.