The crystalline lens is a transparent biconvex formation, located behind the iris (the colored part of the eye) and helps focusing on images of the environment to the retina.
The blurring of any part of the lens and for any reason is called cataract.
Although cataract several think that is connected with old aged prople, the truth is that any age can be affected. The symptoms vary depending on the extent, location and extent of the clouding, but its constant feature is always a decreasing in vision.
The cataract which is present at birth is called congenital cataract.
It is perfectly normal for parents to want to know exactly what caused the cataract to their children.
As in the cases of cataract in adults, the only workaround is to surgically remove the cloudy lens and replace it with an artificial one.