Looking people straight in the eye may or may not reveal their honesty -- but the eyes *can* tell you about cholesterol, liver disease, or diabetes, if you know what to look for. ""The eye is a unique window into health,"" says ophthalmologist Andrew Iwach, spokesperson for the American Academy of Ophthalmology (AAO) and executive director of the Glaucoma Center of San Francisco. ""It's the only place in the body where, without surgery, we can look in and see veins, arteries, and a nerve (the optic nerve)."" The eyes' transparency explains why common eye diseases such as glaucoma, cataracts, and macular degeneration can be detected early with regular eye exams. ""Unfortunately, people get busy and delay not only eye exams but regular physicals. That's why eye doctors sometimes discover other issues, like diabetes or high blood pressure,"" Iwach says. Especially vulnerable, he says: People like caregivers, who worry about others around them while neglecting care for themselves. Keep your eyes out for these 12 problems. - Red flag: Disappearing eyebrows What it means: Shaved eyebrows are a fad (or fashion, if you will) in some circles. But when the outer third of the brow (the part closest to the ears) starts to disappear on its own, this is a common sign of thyroid disease -- either hyperthyroidism (overactive thyroid gland) or hypothyroidism (underactive thyroid gland). The thyroid is a small but critical gland that helps regulate metabolism, and thyroid hormones are among those critical to hair production. What to do: Mention this symptom to a dermatologist or your regular doctor. Most other symptoms of both hyper- and hypothyroidism are notoriously broad and general. Before you see a doctor, make note of any other changes you've noticed, possibly concerning weight, energy levels, bowel or menstrual regularity, mood, or skin changes. - Red flag: A stye that won't go away What it means: The vast majority of the time, a small, raised, often reddish bump along the inner or outer eyelid margin is just an unsightly but innocuous stye (also called a ""chalazion""). But if the spot doesn't clear up in three months, or seems to keep recurring in the same location, it can also be a rare cancer (sebaceous gland carcinoma). What to do: Point out a persistent stye to an ophthalmologist (a medical doctor who specializes in the eye). A biopsy can confirm the diagnosis. Stye is usually removed surgically. - Red flag: Bumpy yellowish patches on the eyelid What it means: Xanthelasma palpebra, the medical name for these tiny yellow bumps are usually a warning that you may have high cholesterol. They're also called ""cholesterol bumps"" -- they're basically fatty deposits. What to do: See your doctor or a skin or eye specialist. A diagnosis can usually be made by sight. An ophthalmologist can also examine the eye and see deposits; for this reason, in fact, sometimes high cholesterol is first diagnosed during a routine eye exam. The problem usually isn't serious and doesn't cause pain or vision problems. A physician will also evaluate you for other signs of coronary artery disease. - Red flag: Burning eyes, blurry vision while using a computer What it means: You might be a workaholic, and you definitely have ""computer vision syndrome"" (CVS). The eyestrain is partly caused by the lack of contrast on a computer screen (compared with ink on paper) and the extra work involved in focusing on pixels of light. What's more, by midlife the eyes lose some of their ability to produce lubricating tears. Irritation sets in, adding to blurriness and discomfort. What to do: Reduce glare by closing window shades, investing in a computer hood, or checking out antireflective coating for your glasses (if you wear them). Simply tinkering with the contrast of your screen can help, too. White areas should neither glow brightly like a light source nor appear gray. Flat-panel LCD display screens (like those on laptops) cause less eyestrain than older models. Keep reference material close to the same height as your monitor, giving your eyes a break from having to refocus so much. - Red flag: Increasing gunk in the eye What it means: Blepharitis -- inflammation of the eyelids, especially at the edges -- can have several causes. Two of them, surprisingly, are conditions better associated with other body parts: scalp dandruff and acne rosacea (which causes flushed red skin, usually in the faces of fair-skinned women at midlife). What to do: With clean hands, apply a warm, damp washcloth to the eyes for about five minutes at a time to loosen debris and soothe the skin. See a doctor, who may prescribe an antibiotic ointment or oral antibiotics, as well as artificial tears. - Red flag: A small blind spot in your vision, with shimmering lights or a wavy line What it means: An ocular migraine (also called an ""ophthalmic migraine,"" ""optical migraine,"" or ""migraine aura"") produces this disturbed vision, with or without an accompanying headache. Changes in blood flow to the brain are thought to be the cause. What to do: If you're driving, pull over until the phenomenon passes (usually within an hour). Do have an eye specialist check it out if vision impairment lasts more than an hour or so, to rule out serious problems such as a retinal tear; or if you also experience other symptoms elsewhere that could indicate stroke or seizure (such as fever, loss of muscle strength, or speech impairment). - Red flag: Red, itchy eyes What it means: Many things can irritate eyes, but itchiness accompanied by sneezing, coughing, sinus congestion, and/or a runny nose, usually screams ""I'm allergic!"" When the eyes are involved, the trigger is usually airborne, like pollen, dust, or animal dander. What to do: Staying away from the allergic trigger is the usual treatment. Antihistamines can treat the itchiness; those in eye-drop or gel form deliver relief to the eyes faster. If the problem turns out to be an allergy to eye drops, look for a preservative-free brand. - Red flag: Whites of the eye turned yellowish What it means: Two groups of people most often show this symptom, known as jaundice: Newborns with immature liver function and adults with problems of the liver, gallbladder, or bile ducts, including hepatitis and cirrhosis. The yellow in the white part of the eye (the sclera) is caused by a buildup of bilirubin, the by-product of old red blood cells the liver can't process. What to do: Mention the symptom to a doctor if the person isn't already under care for a liver-related disease, so the jaundice can be evaluated and the underlying cause treated. - Red flag: A bump or brown spot on the eyelid What it means: Even people who are vigilant about checking their skin may overlook the eyelid as a spot where skin cancer can strike. Most malignant eyelid tumors are basal cell carcinoma. When such a tumor appears as a brown spot, then -- as with any other form of skin cancer -- it's more likely to be malignant melanoma. What to do: Always have any suspicious skin spots or sores checked out by a dermatologist, family physician, or eye doctor. Early detection is critical, before the problem spreads to nearby lymph nodes. - Red flag: Eyes that seem to bulge What it means: The most common cause of protruding eyes is hyperthyroidism (overactivity of the thyroid gland), especially the form known as Graves' disease. What to do: Mention the symptom to a doctor, especially if it's present in tandem with other signs of Graves' disease, including blurry vision, restlessness, fatigue, increase in appetite, weight loss, tremors, and palpitations. A blood test can measure thyroid levels. Treatment includes medication and surgery. - Red flag: Sudden double vision, dim vision, or loss of vision What it means: These are the visual warning signs of stroke. What to do: Seek immediate medical help by calling 911(or your local emergency number). - Red flag: Dry eyes that are sensitive to light What it means: Sjogren's (pronounced ""show-grins"") syndrome is an immune system disorder. It impairs the glands in the eyes and mouth that keep them moist. What to do: A doctor can diagnose Sjogren's through testing. Artificial lubricants (such as artificial tears) are usually necessary to protect the eyes, as well as to improve eating. Drinking plenty of water also helps. (Source: Health.yahoo.net)