While the factors causing cataracts in humans are unknown, there are some predictions among medical professionals. These cataracts seem to occur in mankind due to changes in the protein structure present within the lens of your eyes. They can also be present in child by birth or from its early childhood due to hereditary enzyme defects, systematic congenital infection or genetic disease. Eye surgery, severe eye trauma and intraocular inflammation may also lead to cataracts. Other factors that contribute to the cause of eye cataracts are excessive exposure to ultraviolet light, exposure to ionized radiation, smoking and the use of specific medications like topical, oral, inhaled steroids(anti asthma pumps).