Sleeping with contact lenses in place can cause eye dryness and irritation, and may increase the risk of eye infection and eye damage.

Blocked tear ducts cause excessive tearing and eye irritation when your tears cannot drain normally. Typically, tears drain out of small holes in the corner of your eye, and then pass through tiny tubes into the nose to be eliminated.

Fluid under the eyes causes puffiness and swelling. Although genetic factors and aging render some more susceptible to fluid retention than others, certain style factors and health conditions influence fluid accumulation under the eyes.

Gluten, the protein found in certain grains, might cause health problems, including celiac disease. This condition results from the body’s inability to absorb gluten, and might damage the inner lining of the intestines. Celiac disease might result in digestive problems such as diarrhea and bloating.

Squinting occurs when a person wrinkles her brow and brings the upper and lower eyelids closer together. The wrinkled brow often distinguishes squinting from a person who has a naturally narrow opening between eyelids. If frequent or constant squinting occurs, a person should have an eye exam to determine the cause.

Overdosing on garlic can cause more than a distinctive and pungent odor. While garlic has a number of potential health benefits, too much garlic can interfere with blood clotting, reports a 2007 study published in "Molecular Nutrition and Food Research."

Bleeding can occur in any part of the eye, from the superficial external outer layer, the conjunctiva, to the lining of the back of the eye, the retina. Eye hemorrhages may cause no symptoms at all or cause total vision loss and severe pain, depending on the location.

Regular weight lifting exercises may lead to an increase in the risk for eyesight related issues such as glaucoma and eye floaters.

The skin surrounding your eyes is very delicate. Due to its thin nature and constant exposure, the skin in this area has a higher risk of developing several types of skin problems.

White eye discharge typically signals eye irritation, which can occur with a variety of eye ailments. Irritation of the conjunctiva -- the thin tissue that lines the eyelids and covers the surface of the eye -- is the most common cause. Conditions affecting the eyelids are also frequently to blame.

Neurologists specialize in disorders and diseases that affect the brain and the nervous system. Since the eyes can be affected by some of these conditions, doctors who specialize in neurology may be needed to diagnose and treat certain visual conditions.

Freckles, small accumulations of melanin or pigment, appear anywhere on the skin and sometimes in the eye, accounting for the majority of eye spots. In most cases, an eye freckle can only be seen by an opthalmologist. This is especially true if the freckle occurs inside the colored portion, or the iris, of the eye.