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Understanding cataracts
Audience: patients-public, students-learners ยท Review state: published
What it is
A cataract is a clouding of the lens, the clear part of the eye that focuses light onto the retina. As the lens clouds, vision becomes blurry, hazy, or less colorful, a bit like looking through a fogged window.
Cataracts are very common with age and usually develop slowly in both eyes, though one eye may be worse than the other.
Symptoms
Common signs include cloudy or blurred vision, glare from lamps or sunlight, halos around lights, poor night vision, and colors that look faded or yellowed. Frequent changes in glasses prescription can also be a clue.
Cataracts do not hurt and do not cause redness; painless, gradual vision change is their typical pattern.
Causes and risk factors
Aging is by far the most common cause. Others include diabetes, smoking, long-term corticosteroid use, excessive sunlight exposure over a lifetime, eye injury or surgery, and heavy alcohol use. Some children are born with cataracts or develop them early.
Wearing sunglasses that block ultraviolet light, not smoking, and managing diabetes help lower the risk or slow progression.
Treatment
Early on, brighter lighting and a new glasses prescription can be enough. When vision loss interferes with daily life, surgery is the answer: the cloudy lens is removed and replaced with a clear artificial lens.
Cataract surgery is one of the most common and successful operations in medicine, usually done as a day procedure with local anesthesia. An eye examination confirms the diagnosis and rules out other causes of vision loss, so anyone with these symptoms should see an eye care professional.
Limitations
General educational overview, not medical advice and not a diagnosis. Many conditions blur vision; diagnosis and surgery timing belong with an eye care professional.