The cornea (CORN-ee-uh) is the clear, domed part that covers the front of your eye. When your cornea isn't perfectly round, a condition exists known as astigmatism (uh-STIG-muh-tiz-um).

Blepharitis (blef-uh-RYE-tis) is the general term for inflammation of the eyelids, characterized by flaky particles, itching, swelling, and a chronic redness or pinkness at the edges of your eyelids.

The white of your eye, called the sclera (SKLER-uh), is covered by a thin, slippery membrane called the "conjunctiva" (con-junk-TIE-vuh). The most common problems that can cause the appearance of blood on the white of your eye are the various forms of conjunctivitis (kun-junk-tiv-EYE-tis) and subconjunctival (sub-con-junk-TIE-vul) hemorrhage.

A cataract is a gradual clouding of the lens of your eye, resulting in a loss of vision that can vary tremendously from person to person. It can occur before age 40, although more commonly after age 50, as the lens of your eye thickens, hardens, and loses transparency as part of the normal aging process.

There are three basic types of eye care professionals: ophthalmologists (off-thul-MAHL-uh-jists), optometrists (op-TOM-uh-trists), and opticians. The former is a medical doctor, while the last two dispense glasses and contact lenses.

Color blindness, also known as "color vision deficiency," is a condition that means your ability to distinguish some colors and shades is less than normal.

The eye disorder known as "strabismus" (struh-BIZ-muss), or crossed eyes, also called "squint," occurs when one or both of your eyes turns in, out, up, or down.

The eye disorder known as "strabismus" (struh-BIZ-muss), or crossed eyes, also called "squint,"occurs when one or both eyes turns in, out, up, or down.

Eye cysts can be of several different types, both inside the eye and on the lid. Treatment is determined by the cause, location, and character of the cyst.

The retina (RET-uh-nuh) is the inner layer of tissue in the back of the eye on which your eye focuses light rays. A detached retina is a serious condition in which the retina has separated from the outer layers of the eye.

Diabetic retinopathy (ret-un-AW-puh-the) is a general term for all disorders of the retina caused by diabetes. Several factors can influence whether you contract (cun-TRACT) retinopathy, including your blood glucose control, blood pressure level, how long you've had diabetes, and your genes.

When your eye doesn't produce enough tears, it may result in "dry eye," an eye condition stemming from an imbalance in the quantity or the quality of tears.

Getting your eyes checked can be a fairly simple procedure or a complicated one, depending on how in-depth the exam is and whether there's a problem. A routine exam can be performed by an ophthalmologist (off-thul-MAHL-uh-jist), a medical doctor, or an optometrist, a doctor of optometry.

If you can see things well that are at a distance, but you have trouble seeing things close up, such as when you're reading, you may be farsighted. Farsightedness, whose medical name is "hyperopia (high-per-OH-pee-uh)," is a vision disorder, the result of which is that distant objects are usually seen clearly, but close ones don't come into proper focus.

"Lazy eye" is the common term for the medical condition, amblyopia (am-blee-OH-pee-uh). It occurs in children when a child's eye becomes misaligned-- such as crossed or turned out-- which causes the brain to ignore the image coming from the turned eye.

If you don't have trouble seeing things close up, such as when you're reading or using a computer, but you have difficulty seeing things at a distance, you may be nearsighted.

Two types of eye care professionals are optometrists and ophthalmologists. An "ophthalmologist" (off-thul-MAHL-uh-jist) is a medical doctor with an M.

Conjunctivitis (kun-junk-tiv-EYE-tis) is an inflammation of the conjunctiva (con-junk-TIE-vuh), the thin, transparent skin covering the white of the eye and inside of the eyelids.

Presbyopia (prez-bee-OH-pee-uh) is a visual disorder that often appears when you reach middle age, usually in your forties. It's not a disease but, rather, a condition caused by the natural aging process of the eye, so it can't be prevented or cured.

A stye (STIGH) is a minor infection of the eye that appears as a lump and develops near, or on, the upper or lower eyelid. It can be very irritating and painful.

A "retinal break" is any disruption in the retina, such as a hole or tear (Tehr). If you're highly nearsighted, have had cataract surgery, or have suffered an eye injury, you may be predisposed to developing retinal tears.

Some degree of tearing (TEER-ing) from eyestrain, fatigue, and irritation from the sun, chemicals, pollutants, and allergens (AL-ler-jens) is essentially normal.