Cataracts are a cloudy area in the lens of the eye that develops slowly and causes vision to deteriorate. They are common in older adults, with over half of those over 80 having cataracts. Symptoms include blurry vision, trouble seeing at night, and faded colors. Cataracts are caused by protein clumping in the lens and can be due to aging, smoking, UV exposure, medications, or diseases like diabetes. Treatment is usually surgery to remove the cloudy lens and replace it with an artificial lens, which is highly effective. Prevention involves protecting eyes from UV rays, eye exams, not smoking, and a healthy lifestyle.