A cataract is a clouding of lens inside the eye that can blur vision. Cataracts occur commonly with age, but they also can be caused by sun exposure, smoking, diabetes and certain medications. It's important to visit your doctor if you experience blurred vision or any other symptoms that seem suspicious. Surgery for cataracts has become sophisticated and routine. It usually takes 20 minutes or less, and patients feel back to normal by the next day, says Jessica Chow, MD, a Yale Medicine Ophthalmology cataract specialist.