People with myopia or nearsightedness have difficulty seeing distant objects, but can clearly see objects that are near. For example, a person who is nearsighted may not be able to make out highway signs until they are just a few feet away.
More than 3 million adult Americans have glaucoma, making it one of the leading causes of blindness in the U.S.
The most common form, chronic open-angle glaucoma, generally appears in middle age and seems to have a genetic component: One in five people with glaucoma has a close relative with the condition. In chronic, open-angle glaucoma, sight begins to fade in the outer areas (peripheral) of the visual field; if untreated, tunnel vision and then blindness follow.
The inside of the eye continuously...
People who are nearsighted have what is called a refractive error. In nearsighted people, the eyeball is too long or the cornea has too much curvature, so the light entering the eye is not focused correctly. Images focus in front of the retina, the light-sensitive part of the eye, rather than directly on the retina, causing blurred vision.
Nearsightedness runs in families and usually appears in childhood. Usually, the condition plateaus, but it can worsen with age.
What Are the Symptoms of Nearsightedness?
People who are nearsighted often complain of headaches, eyestrain, squinting, or fatigue when driving, playing sports, or looking more than a few feet away. Children commonly complain of not being able to see the board at school.
How Is Nearsightedness Diagnosed?
Nearsightedness can be easily diagnosed using standard eye exams given by an eye doctor.
How Is Nearsightedness Treated?
Glasses, contact lenses, or refractive surgery can correct nearsightedness. With myopia, your prescription for glasses or contact lenses is a negative number, such as -3.00. The higher the number, the stronger your lenses will be. The prescription helps the eye focus light on the retina, clearing up the vision.
Refractive surgery can reduce or even eliminate your dependence on glasses or contact lenses. The most common procedures for nearsightedness include:
Photorefractive keratectomy. Also called PRK, this surgery employs a laser to remove a layer of corneal tissue. That flattens the corneal curvature and allows light rays to focus closer to or even on the retina.
Laser-assisted in situ keratomileusis. This surgery is commonly called LASIK. The surgeon uses a femto laser or mechanical instrument to cut a thin flap through the top of the cornea. Then an excimer laser is used to sculp the exposed corneal tissue, and the flap is dropped back into place. LASIK is the most common surgery used to correct nearsightedness.