A cataract is a condition that affects the eye’s natural lens, which lies behind the iris and the pupil. The lens works much like a camera lens, focusing light onto the retina at the back of the eye, and adjusting the eye’s focus to let us see things clearly both up close and far away.
The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and allows light to pass through it. However, as we age, some of the protein may clump together and start to cloud a small area of the lens, creating what we call a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see.
People with cataracts often describe their vision as being similar to looking through a frosty or fogged-up window. This clouding is usually progressive, causing a gradual and painless decrease in vision. Other symptoms can include blurred or hazy vision, less intense color perception, difficulty seeing at night, and seeing halos around lights. If left untreated, a cataract can eventually lead to blindness.
The most common type of cataract is related to aging, but cataracts can also develop in people with diabetes, as a result of smoking, prolonged exposure to sunlight, or long-term steroid use. Sometimes, babies are even born with congenital cataracts.
The good news is that modern cataract surgery is one of the safest and most effective surgical procedures performed today, and can restore vision in most cases.