Aging & Health A to Z
Causes & Symptoms
The proteins in the lens of your eye gradually change shape and clump together as you age. With time, your lens tissue becomes thicker, less flexible, and less transparent. The color of the lens changes too, becoming yellowish as the lens is stained by the protein clumps. Eventually, the discolored lens begins to block the light coming through your pupil. Everything starts to look darker, browner, and less distinct.
Many conditions and lifestyle habits make cataracts more likely to develop. These risk factors include:
- Aging (the most important risk factor)
- Drinking too much alcohol
- Excessive exposure to sunlight
- High blood pressure
- Inadequate vitamin intake
- Excessive exposure to ionizing radiation, such as that used in X-rays and cancer radiation therapy
- Family history of cataracts
- Previous eye injury or inflammation
- Previous eye surgery
- Prolonged use of corticosteroid medications (such as prednisone)
Symptoms and Warning Signs
Cataracts start slowly and affect only a small part of the lens at first. Therefore, most people have no idea that a cataract is present. Often, only one eye is involved in the beginning. Your ability to see things close up or far away will be affected depending on where the cataract is located. The change may be most obvious at night, or you may notice it more in bright daylight. After months or years, your cataract will grow and cover more of the lens, affecting a greater part of your range of vision.
Common signs and symptoms of cataracts are listed below. But these can also be signs of other eye problems. If you have any of these symptoms, you should have a check-up with your eye doctor.
- Cloudy, blurry, or dim vision
- Poor night vision; increased difficulty seeing in the dark
- Sensitivity to light and glare; car headlights, lamps, or sunlight seem too bright
- "Halos" appear around lights
- A need to change eyeglass or contact lens prescriptions more often
- Faded or yellowing colors
- Double vision or multiple images in a single eye (this symptom may disappear as the cataract grows).
If you notice any changes in your vision, have an eye check-up right away. Sudden vision changes, such as double vision or blurring, require an immediate appointment with your health care provider.
Updated: November 2016
Posted: March 2012