The most common cause tends to be ageing due to clumping of proteins in the lens as they begin clouding a small area. Over time, Cataracts can grow bigger, causing more of the lens to become cloudier and making it harder to see. However, Cataracts can be caused by other factors such as:
Congenital Cataracts - when a baby is born or develops Cataracts in childhood
Radiation - causing Cataracts to develop after exposure to some types of radiation
Secondary Cataracts - After surgery for other eye related problems such as glaucoma, or from health issues like diabetes and as well as from certain types of medication
Traumatic Cataract - usually developing after eye injuries