The major causes of cataract are age- or injury-related changes in the tissue making up the lens of a human eye, inherited genetic disorders, past eye surgeries or medical conditions, such as diabetes. A continuing administration of steroid medications is also associated with the development of cataract.

The perceived signs and symptoms of cataract are blurry vision, increased difficulty in seeing during night, increased reactive response to light, the requirement of brighter light source for reading and sudden changes in the power of eyeglasses or contact lens.

Cataracts are treatable with surgery, but not curable. Monitoring and routine check-up of eyes and lifestyle changes are advised for cataract. Thereafter, the affected lens of eyes are surgically removed.

Ageing is the most common risk factor for cataract. Other risk factors include diseases, such as diabetes, and certain medications, such as steroids.

Visual acuity test and slit-lamp examination are employed by an eye doctor to determine the signs of impairment along with other symptoms of cataract. An ophthalmoscope or a slit lamp is employed by an optometrist or eye doctor for the evaluation of lens for cataract symptoms.