The normal process of aging can cause the lens to harden and turn cloudy resulting in senile cataracts. These are the most common type and may occur as early as age 40. Cataracts may develop in children as well as in adults of any age. When they appear in children they may be hereditary or may have been caused by infection or inflammation affecting the pregnant woman and unborn baby. These are called congenital cataracts and are present at birth.
Eye injuries can cause cataracts in people of any age.
A hard blow, puncture, cut, intense heat or chemical burn can damage the lens, resulting in a traumatic cataract. Certain infections or diseases, such as diabetes mellitus , may also cause the lens to cloud resulting in secondary cataracts. Depending on the size and location of the cloudy areas in the lens, a person may or may not be aware that a cataract is developing. If the cataract is located on the outer edge of the lens, no change in vision may be noticed, but if it is located near the centre of the lens, it usually interferes with clear sight. As cataracts develop, there may be hazy, fuzzy and blurred vision.