A cataract is a clouding of 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. The lens also adjusts the eye’s focus, letting us see things clearly both up close and far away.
The lens is mostly made of water and protein. The protein is arranged in a precise way that keeps the lens clear and allows light to pass through it. As we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see.
Most cataracts are age-related. However, cataracts can also be present at birth or occur at any age. Cataracts can also be caused by diseases such as diabetes or can occur as the result of long-term use of certain medications, such as steroids.
Symptoms of Cataracts
A cataract starts out small, and at first has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass. However, as cataracts worsen, you are likely to notice some or all of these problems:
- Blurred vision that cannot be corrected with a change in your glasses prescription
- Ghost images or double vision in one or both eyes
- Glare from sunlight and artificial light, including oncoming headlights when driving at night
- Colors appear faded and less vibrant