There are four types of cataracts; they are age-related cataracts, secondary cataracts, congenital cataracts and traumatic cataracts respectively, among which the third type indicates that some babies are born with cataracts as a result of an infection, injury, or poor development when they are in their mother's belly. People develop cataracts when protein accumulating in the lens makes it cloudy, which prevents light from passing through the lens, hence leading to loss of vision to some degree. As the new lens cells form, the older cells gather in the center of the lens, as a result of which cataracts develop.
