They "speak volumes," and they're the "windows to the soul." They're the first thing people look at when they talk to you. It seems unjust that your eyes are the first part of your body to reveal your age. No wonder most of us are so hypersensitive to even the slightest imperfections that we notice around our eyes.

These changes occur so quickly because the skin surrounding your eyes is thinner and drier than the skin on the rest of your body. And it doesn't help that you crinkle this fragile skin every time you smile, tug on it when you put in contacts, rub it when you're tired, squint with it, sleep on it, and scrub it each day.

Still, a whopping 90 percent of visible aging -- be it wrinkles, puffiness, or dark circles -- is due to sun damage. The other 10 percent is determined by a hodgepodge of factors, including gravity's effects, as well as how you sleep, eat, drink, and smile, and whether you smoke. (Smoking reduces blood flow to your skin, robbing it of moisture and damaging its collagen and elastin. This causes both wrinkling and sagging.)

The good news is that it's relatively easy to treat most of the signs of aging that irritate us. Here are some suggestions on how to prevent, fix, and hide the small but noticeable problems that plague this most fragile area.

Crow's Feet

As the collagen and elastic fibers in your skin break down, the muscles around your eyes lose their tone, which causes the skin to wrinkle. What causes this deterioration? You can put the blame on all those long weekends spent sunning at the beach years ago -- ultraviolet radiation is the most likely culprit.

Prevent Them: Even if you've already spent years worshiping the sun, it's not too late to prevent further damage -- or perhaps even undo some. When skin is protected from UV rays, it naturally begins to heal itself. Try throwing on a wide-brimmed hat, a pair of wraparound sunglasses with 100 percent UV protection, and an SPF 15 or stronger sunscreen that blocks both UV-B and UV-A rays. To see visible results, though, you'll still need the aid of wrinkle-fighting products.

Fix Them: To remedy some of the damage that's already been done and kick-start new collagen and blood-vessel formation, follow this routine: Every morning, 15 minutes after washing your face, apply a vitamin C lotion such as SkinCeuticals Serum 10 Topical Vitamin C. Wait a minute, then apply an alpha-hydroxy acid sunscreen, such as Formula 405 Facial Day Cream with SPF 15. At bedtime, after cleansing your face, reapply the vitamin C, wait for a minute, then follow up with either doctor-prescribed Renova or an over-the-counter retinol cream. If you want to use the former, start with the weaker .02 percent concentration to prevent irritation since you're using a combination of products, suggests Nelson Lee Novick, M.D., a New York City dermatologist and author of Super Skin (Universe Press).

Hide Them: Some high-tech foundations and pre-foundation formulations contain ingredients that are capable of deflecting or diffusing light to help soften or blur the appearance of wrinkles. (Look for the words "deflect" or "diffuse" on the label.) You'll find these agents, for example, in Prescriptives Magic Illuminating Potion. For more coverage, apply concealer, but keep it light; caked-on makeup accentuates wrinkles. Use your ring finger, which produces the least amount of pressure, and let the concealer warm up on your finger before applying it. Tap it on starting from the outside of your eye moving toward the inside near your nose, pressing it in without rubbing. To avoid drawing attention to wrinkles, use a neutral eyeliner or shadow in a matte formulation rather than a bright blue or green.

Puffiness

The reasons behind puffy eyes run the gamut: hay fever, an allergic reaction to cosmetics, fluid retention from sleeping too much or too little, or from eating too much salt. And structural changes in under-eye muscles resulting from aging can also cause blood vessels to become more prominent.

Prevent It: Since the puffiness may be caused by one of the problems listed above, the easiest and most effective solution is to do the obvious: treat your allergies, get more sleep, and eat less salt.

Fix It: To disperse fluid buildup, apply anything that's chilled, like the back of a spoon soaked in ice water, cool cucumber slices, or a refrigerated soft gel mask. If this doesn't help and your problem is chronic, it's probably not fluid retention. See your dermatologist for other treatment options.

Hide It: Apply a shade slightly darker than your natural skin tone directly on the prominent area to make it recede and a slightly lighter shade in the furrow below. Then smile -- it makes the puffs show less.

Dark Circles

Two major causes for puffy, swollen eyes -- allergies and lack of sleep -- can also cause dark circles, so fixing one problem may help the other. Darkness may really be a shadow beneath the protruding area. Or it may also be that you've inherited thin, transparent skin, which naturally shows the blueness of blood vessels.

Prevent Them: Try getting more sleep or taking care of allergies.

Fix Them: If dilated blood vessels are your problem, topical vitamin K, originally used to treat black and blue marks, may reduce their appearance. Apply a five percent vitamin K cream, such as Advanced ResKue Topical Vitamin K Cream 5 percent twice a day, 15 minutes after washing. Then apply a retinol cream or Renova a minute later, followed by sunscreen, Novick says. Dermatologists also recommend hydroquinone or kojic acid creams to lighten the skin, but they don't always reach deep enough to affect the pigment. A laser or medium phenol peel can also lighten the skin if nothing else helps, and it will smooth out fine lines. Just be sure to find a skilled doctor who can feather the edges so your eyes don't look noticeably lighter than the rest of your face.

Hide Them: Never wear eyeliner or mascara on bottom lashes when you have dark circles. Instead, double up on liner above the eyes to draw attention away. If your circles are blue or purplish, use a yellow-based corrector under your eyes. If they're brown, a slightly pinkish-red corrector under your concealer will help neutralize the darkness. Under-eye shadows are also less noticeable when the color of your eyes stands out. Showcase your eye color by using contrasting shadows and liners. For example, blue eyes should wear warm colors, like browns and yellows, while green or brown eyes should wear cool tones. Avoid a purple-dominated color, which will draw attention to circles.

Dry Skin and Fine Lines

It isn't the underlying cause of wrinkles, but dry skin does accentuate their appearance. The eye area is especially vulnerable to dryness because it doesn't have oil glands. Many people overwash, overbuff, or use too harsh a cleanser, and their skin ends up parched and flaky, which makes lines stand out even more.

Prevent Them: If you're chronically dehydrated, it will show in your skin. So by all means, you should drink more water. It might help alleviate some of the problem.

Fix Them: If you're at all dry, try using a good moisturizer for a couple weeks before investing in expensive treatments. It may help fine lines practically disappear. For an inexpensive, hypoallergenic, and noncomedogenic brand, Novick recommends Carmol 10. It contains urea, a natural moisturizer produced by your body; in this product's 10 percent concentration, the chemical also mildly exfoliates. For best results, wet your face, then apply a moisturizer immediately afterward to lock in the water and prevent evaporation.

Hide Them: Always apply eye cream before makeup. Without it, dry skin will suck the moisture from your foundation or concealer, making it cakey and magnifying creases.