• Long-term exposure to ultraviolet light
• Eye diseases such as iris inflammation, eye infection
• Underlying diseases such as diabetes, high blood pressure and thyroid disease
• Eye injury or inflammation
• Congenital defect caused by maternal infection with rubella
• Long-term use of steroid medications 

• Blurred/dim vision with no pain in bright light, but almost normal vision at night
• Double vision caused by a clouding of the lens and refractive error (light rays enter the eye but are not focused at a single point on the retina)
• Seeing halos around lights, such as when driving at night
• The need to frequently change eyeglasses, better near vision without eyeglasses
• White opacity in the center of the pupil 

Cataract surgery involves removing the clouded lens and replacing it with a clear artificial lens. The following surgical techniques can be used to achieve this:

• Phacoemulsification
• Femtosecond laser

• Get enough sleep
• Choose a healthy diet
• Give your eyes a break from time to time after long hours of focusing, such as from reading or using a computer
• Wear sunglasses that block ultraviolet light, do not look directly at the sun
• Avoid eye injuries and accidents
• Have your eyes checked regularly. People over the age of 40 should have their eyes tested once a year.