To understand astigmatism, it is helpful to think of the normal eye as evenly rounded, like a basketball. With astigmatism, the eye is egg- or oval-shaped like an American football. There are two basic types of astigmatism: horizontal astigmatism (when the eye is wider than it is tall), and vertical

Black eye is a phrase used to describe bruising around the eye due to an injury to the face or the head. Blood and other fluids collect in the space around the eye, causing swelling and dark bruising in the tissue. When there is trauma or injury to the face, the skin around the eye — which is very

Color blindness occurs when you are unable to see colors in a normal way. Color blindness often happens when someone cannot distinguish between certain colors. This usually happens between greens and reds, and occasionally blues. Color blindness can happen when one or more of the color cone cells are

Millions of people choose to wear contact lenses, rather than eyeglasses, to correct vision problems. There are many different types of lenses available to help correct refractive errors. It is important to remember that contacts are not fashion accessories or cosmetics. They are medical devices that

Blue light is part of the visible light spectrum. While excessive exposure to blue light from the sun without sunglasses can be harmful, the small amount of blue light from computers does not damage the eye. There is no need to spend money on special blue light blocking eyeglasses. Instead, take short

Your eye doctor will put a small amount of dilating eye drops into each of your eyes. It usually takes about 20 to 30 minutes for your pupils to fully open. Light-colored eyes (such as blue, green or hazel) will dilate faster than brown eyes. While your eyes are dilated, your vision will be blurry. You

Farsightedness is a refractive error. Because the eyeball is too short (from front to back) or the cornea is too steep, light does not refract (bend) properly as it travels through the eye. Most farsighted people have clear distance vision, but their near vision is blurry. Symptoms include eyestrain,

Nearsightedness is when close-up objects look clear but distant objects are blurry. Nearsightedness is a common eye focusing disorder. The nearsighted eye is too long or too steeply curved. Light then falls short of the retina causing blurry vision. Other symptoms include squinting, eye strain, or difficulty

Presbyopia (“aging eye”) is when your eyes gradually lose the ability to see things clearly up close. It is a normal part of aging. To improve your vision, you can wear glasses that offer vision correction for both near and far (such as bifocals). You can also try monovision, where one eye is corrected

Refractive errors are vision problems that happen when your eye does not refract (bend) light properly. When your cornea or lens does not focus light properly on the retina, your vision is blurry. There are four basic refractive errors: myopia (nearsightedness), hyperopia (farsightedness), astigmatism

A stye (hordeolum) is a small, painful bump at the base of your eyelash or under the eyelid. It often causes the eyelid to swell. A chalazion is a larger red lump on the eyelid. A chalazion is not usually very painful, and it usually doesn’t cause the entire eyelid to swell. Treatments range from warm

Subconjunctival hemorrhage is a blood spot on the white of your eye. It looks serious, but it is usually harmless. Subconjunctival hemorrhage is caused by a broken blood vessel in the eye, which often happens when coughing, sneezing or straining leads to a quick rise in blood pressure. Trauma to the