Are your eyes often red or dry? Or do they sting, burn or feel gritty at work? You may have dry eye syndrome, an often hard-to-diagnose condition that affects more than 20 million Americans. Prolonged computer use, reading and exposure to heating, air-conditioning and dust can contribute to this condition. To prevent dry eyes, take breaks from your computer, use a humidifier when indoor heat is on, limit caffeine (which is dehydrating) and drink at least six to eight glasses of water a day. If you have any of the aforementioned symptoms, see your eye doctor, who may prescribe eye drops. If left untreated, chronic dry eye can increase your risk for impaired vision and eye infections.