Behind your eye's pupil is a lens that focuses light. In a healthy eye, this lens is clear. A cataract is a clouding of the lens. A cataract blocks light and can interfere with your vision.
Lenses are mostly made of protein and water. A cataract forms when the protein in the lens begins to clump. This can happen naturally as you get older. It can result from an eye injury. Cataracts are also linked to certain medications, exposure to excessive sunlight, smoking and other factors.
Cataracts can form in one or both of your eyes. A cataract on the edge of the eye's lens may not affect your vision. But a cataract in the center of the lens can make your vision yellowish and cloudy. This can happen very gradually. You may not notice it at first, but over time your vision can worsen. Colors may fade, and things may seem blurry. You may have problems with glare. You may need brighter light to read. You may have poor vision at night. And you may have double vision in one eye.
Glasses, magnifying lenses and brighter lights can help during the early stages of a cataract. But when these no longer help, your cataract can be corrected with surgery. Your eye doctor can create a care plan that is right for you.