Cataracts Causes, Symptoms and Treatments
A cataract is a clouding of the lens in your eye. It affects your vision. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.

A cataract can occur in either or both eyes. It cannot spread from one eye to the other. Common symptoms are:

Blurry vision
Colors that seem faded
Glare headlights, lamps or sunlight may seem too bright. You may also see a halo around lights.
Not being able to see well at night
Double vision
Frequent prescription changes in your eye wear

Cataracts usually develop slowly. New glasses, brighter lighting, antiglare sunglasses or magnifying lenses can help at first. Surgery is also an option. It involves removing the cloudy lens and replacing it with an artificial lens. Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataracts.

NIH: National Eye Institute