Cataracts are one of the most common eye problems that affect humans as we age. By age 75, more than 70 percent of Americans have vision problems because of cataracts. Cataracts are even more common than other eye problems such as glaucoma and macular degeneration, but rarely cause blindness in this country because they can be treated.

A cataract is a clouding of the lens of the eye. Since the lens helps us focus on objects, clouding of the lens makes it difficult to focus clearly. Cataracts develop slowly, so the clouding becomes gradually worse over time. Cataracts can develop in one eye or both eyes. They are not painful.

People with cataracts usually experience one or more of these symptoms:

Blurred, filmy or cloudy vision.

Increased sensitivity to light and glare at night.

Poor night vision.

Need for bright light to read.

Increased nearsightedness.

Changes in the color of the pupil of the eye.

Double vision in one eye.

Cataracts develop in the eye because aging, especially after age 50.

They can run in families. Other risk factors include: premature birth, diabetes, smoking, previous eye injury, previous eye surgery or long-term treatment with steroid medications.

Another risk factor is long-term exposure to bright sunlight without wearing sunglasses. If you work outdoors or spend much time outside, invest in good-quality sunglasses with UV protection. It’s the UV (ultraviolet) rays from the sun that cause eye damage. If you wear regular glasses, be sure they have anti-UV coating. Wearing a hat with a brim that casts a shadow over your eyes can also help.

Eye doctors – ophthalmologists and optometrists – can detect cataracts by doing a simple eye exam.

Many people with cataracts can see quite well; cataracts don’t always affect vision enough to interfere with the ability to function well in daily life. If a person with a cataract can see well enough to drive safely, read comfortably, watch television, use a computer and participate in all their usual activities, no treatment is necessary.

The only treatment available is surgery to remove the cataract.

Cataract removal surgery is one of the most common surgeries in the world, and is usually successful. The American Academy of Ophthalmologists reports 95 percent of cataract surgeries result in improved vision.

Cataract surgery is an outpatient procedure, meaning patients do not need to stay overnight in the hospital. Local anesthesia is used so the surgery is not painful. Your eyes may feel uncomfortable for a few days after the surgery as they heal.

During cataract surgery, the clouded lens is removed and is replaced with an intraocular lens made of clear plastic. The lens implant becomes a permanent part of the eye; it does not require any special care. Many people require reading glasses after they have cataract surgery.

If a person has cataracts in both eyes, surgery is usually done on one eye at a time; the second eye is done a month or two after the first eye heals.

Human are not the only ones to suffer from cataracts. Dogs, cats, ferrets, horses, birds, reptiles and other species can also develop cataracts. In animals with large eyes, cataracts can be quite easy to see. The pupil of the eye will look cloudy or discolored. Veterinarians can perform cataract surgery on animals; the procedure is very similar to the surgery done on humans.

Kathryn B. Brown is a family nurse practitioner with a master’s degree in nursing from OHSU. Is there a health topic you would like to read about? Send ideas to kbbrown@eastoregonian.com. you can find more local health news and information in the Health section at www.dailyastorian.info