Sure, mom used to scold you about sitting too close to the TV, but that's not the only thing that could be hurting your eyes. 1. Not wearing sunglasses Remember when Anderson Cooper wore that eye patch? He sunburned his eyes while jet skiing in Portugal on a "60 Minutes" assignment, and while he didn't technically lose his sight, he wore it to protect his eye while it healed. If you don't want that to happen to you, always wear a broad-brimmed hat and shades, making sure they protect against ultraviolet rays (look for a special sticker that says, "100 percent UV blocking"). Exposure to UV rays damages the retina and increases your risk of cloudiness on your eye, also known as cataracts. It also makes you more likely to get skin cancer on your eyelids, says Vinay Aakalu, M.D., assistant professor of ophthalmology and ocular facial plastic surgery at the University of Illinois at Chicago.Overexposure to the sun's rays can also lead to ultraviolet keratitis -- sunburn on the epithelium of the cornea (the clear outer part of the eye) -- which you can get when skiing or even in a tanning booth, if you skip the protective goggles. Like sunburn, it can sneak up on you: Pain, blurry vision, and tearing can start hours later. 2. Overusing eye drops Drops that take the red out make your eyes look better because they temporarily constrict blood vessels, but the inflammation can come back. "After a few hours, they stop working, and the blood vessels dilate, making the eyes often appear redder than they were to start," says Stephanie Marioneaux, M.D., an ophthalmologist and clinical spokesperson for the American Academy of Ophthalmology. 3. Improperly treating dry eyes About 3.5 million women and 1.5 million men in the U.S. suffer from moderate to severe ocular dryness (a.k.a. "dry eyes"). Lubricating drops usually come in bottles with preservatives and using them too many times can actually irritate your eyes. It's more costly, but better, to get individual blister packs of artificial tears if you're going to use them more than four times a day. If you're treating itchy eyes, keep your drops in the refrigerator. "The coolness helps to take away that itchy sensation," says Artis Montague, M.D., an ophthalmologist who is clinic director of Stanford's Byers Eye Institute. Also, avoid rubbing your dry eyes, and use a humidifier to increase moisture in your home. 4. Staring too long at a screen Blinking helps distribute fluid throughout your eyes. But when you focus on a computer, you blink less often than usual. "You should be blinking 12 to 15 times per minute, so staring at the computer generally means you are not blinking enough," says Marioneaux. "Your tears evaporate, your vision becomes smeary, and your eyes may burn and water. Blink!" Reading very small print for prolonged periods of time causes your eyes to work too hard, so be sure to look up from your screen and look at something far away every so often. One more reason to decrease screen time: New data suggests that looking at small print on mobile devices may stimulate the gene for nearsightedness. 5. Being careless with your contact lenses Use fresh cleaning solution daily and never put them in your mouth or rinse them in water, says Marioneaux. Many ophthalmologists recommend daily disposables. And never wear contact lenses in the shower, hot tubs, swimming pools, or the ocean. To ensure your eyes get enough oxygen, don't sleep in your contacts. Also, don't just order lenses without seeing an eye doctor to get them fit properly. Otherwise, you increase your risk of getting infections. "If the contact lens fits like a suction cup, then removing it may cause a small scratch on the cornea, which becomes an entry for bad bacteria that may cause serious eye infections," says Marioneaux. 6. Using old makeup -- and sleeping in it To avoid exposure to infection-causing bacteria, toss cosmetics after three months, according to the American Academy of Ophthalmology. And always, always remove your makeup before bed. 7. Not wearing goggles Don't just save your goggles for swimming. If you're mowing the lawn, using a weed whacker, or doing home repairs, put some on to protect yourself from any flying debris, which can cause abrasions in the cornea. Make sure anyone nearby, especially children, also have protective eyewear on. 8. Smoking You shouldn't be smoking for a lot of reasons, but here's another one: It increases the risk of cataracts and macular degeneration (the progressive deterioration of part of the retina). "It impairs the ability of your body to provide adequate nutrition and oxygenation to tissues, and that includes the tissues in your eye," says Ian Conner, M.D., an assistant professor of ophthalmology at the University of Pittsburgh School of Medicine. 9. Skipping regular eye exams Visit the ophthalmologist -- especially if you have eye-affecting conditions such as high blood pressure and diabetes. Uncontrolled diabetes can lead to blindness, warns Montague. 10. Ignoring symptoms Don't assume that flashing lights, pain, fuzzy vision, redness, or light sensitivity will vanish automatically, says Anne Sumers, M.D., an ophthalmologist who is a clinical spokesperson for the American Academy of Ophthalmology. "To me, the five most dangerous words in the English language are, 'Maybe it will go away.'" If you see things floating around and then turning fuzzy, it could mean your retina is coming off, she says. Get to the ophthalmologist quickly: "A delay in diagnosis can mean much more complex surgery and a more guarded prognosis for recovery of vision."