Introduction to myopia
Myopia (or nearsightedness) affects 20% to 30% of the population, but this eye disorder is easily corrected with eyeglasses, contact lenses or surgery.
People who have myopia or nearsightedness have difficulty seeing distant objects, but can see objects that are near clearly. For example, a person who is nearsighted may not be able to make out highway signs until they are just a few feet away.
What Causes Myopia?
People who are nearsighted have what is called a refractive error. This means that the light rays bend incorrectly into the eye to transmit images to the brain. In people with myopia, the eyeball is too long or the cornea has too much curvature, so the light entering the eye is not focused correctly. Light rays of images focus in front of the retina, the light-sensitive part of the eye, rather than directly on the retina, causing blurred vision.
Myopia runs in families and usually appears in childhood. Sometimes the condition plateaus, or sometimes it worsens with age.
What Are the Symptoms of Myopia?
People who are nearsighted often complain of headaches, eyestrain, squinting or fatigue when driving, playing sports, or looking more than a few feet away.
How Is Myopia Diagnosed?
Myopia can be easily diagnosed using standard eye exams given by an eye doctor.
How Is Myopia Treated?
Glasses, contact lenses, or refractive surgery can correct myopia.
With myopia, your prescription for glasses or contact lens is a negative number, such as -3.00. The higher the number, the stronger your lenses will be.
Refractive surgery can reduce or even eliminate your dependence on glasses or contact lenses. The most common procedures for myopia are performed with a laser, including:
- Photorefractive keratectomy. Also called PRK , a laser is used to remove a layer of corneal tissue, which flattens the cornea and allows light rays to focus closer to or even on the retina.
- Laser-assisted in situ keratomileusis. Commonly called LASIK , a laser is used to cut a flap through the top of the cornea, a laser removes some corneal tissue, then the flap is dropped back into place. LASIK is the most common surgery used to correct nearsightedness.
- Corneal rings. Plastic corneal rings, called Intacs, are implanted into the eye to alter the shape of the cornea. One advantage of the rings is that they may be left in place permanently, may be removed in case of a problem, or adjusted should a prescription change be necessary.
Reviewed by the doctors at The Cleveland Clinic Cole Eye Institute.
Edited by Charlotte E. Grayson, MD, WebMD, October 2004.
IMAGES
Myopia See a picture of eye diseases and conditions See ImagesHealth Solutions From Our Sponsors
Top Myopia Related Articles
Cataract Surgery
Cataract surgery is a surgical procedure in which a small incision is made in the surface of the eye in or near the cornea and a thin ultrasound probe is inserted into the eye so ultrasonic vibrations can dissolve the clouded lens. These tiny pieces are sucked out through the probe and an artificial lens is placed in the space the cataract occupied.
Eye Diseases Slideshow
Eye diseases can cause damage and blindness if not detected and treated soon enough. Learn the warning signs and symptoms of common eye conditions such as glaucoma, cataracts, pink eye, macular degeneration and more.
Eye Floaters
Eye floaters are deposits or condensation that forms in the eye's vitreous humor. These deposits cast shadows on the retina, and as the eye moves, the deposits shift position, making it appear as though the shadows are moving or floating.
Eye Strain
Eye strain is a symptom caused by looking at something for a long time. Symptoms and signs include redness, light sensitivity, headaches, and blurred vision. Symptoms may be treated by closing the eyes and taking a break from the visual task.
Eyewear Slideshow
Learn about your eye care needs and fashion wishes -- with eye glasses, frames and eyewear for computer use, reading, driving, sports and more.
Glaucoma
Glaucoma is a common eye condition in which the fluid pressure inside the eye rises because of slowed fluid drainage from the eye. If untreated, glaucoma may damage the optic nerve and other parts of the eye, causing the loss of vision or even blindness.
Laser Eye Surgery
How does LASIK work? Get information on this popular laser eye surgery, the procedure, success rates, and possible vision side effects.
LASIK Eye Surgery
LASIK (laser in situ keratomileusis) eye surgery is a procedure in which a laser is used beneath the corneal flap to reshape the cornea. This process is used to:- treat refractive errors,
- improve vision,
- and eliminate or reduce the need for contact lenses or glasses.
- conventional LASIK,
- wavefront-optimized LASIK,
- and wavefront-guided LASIK.
Nearsightedness Picture
Nearsightedness affects 20%-30% of the population, but this eye disorder is easily corrected with eyeglasses, contact lenses or surgery. See a picture of Nearsightedness and learn more about the health topic.
Phakic Intraocular Lenses
Phakic intraocular lenses are devices that are permanently implanted to into the eye to reduce a person's need for glasses or contact lenses. The lenses are surgically implanted in front of or behind the iris. Phakic lenses help correct nearsightedness. Risks of the procedure include vision loss, increased intraocular pressure, and the development of cataracts or retinal detachment.
Photorefractive Keratectomy
PRK is a type of laser eye surgery that is used to correct nearsightedness, farsightedness, and astigmatism. The procedure involves using a laser to reshape the cornea. Potential side effects include seeing a mirror glare, seeing mild halos, and loss of best vision achieved with glasses.
Puberty
The time when boys and girls begin the process of sexual maturation is called puberty. During this time, both sexes undergo a series of biological changes that include a rapid increase in height, bone growth, weight increase, the growth of pubic hair, breast development and the onset of menstruation in girls, and testicle, penis, and muscle enlargement in boys.
Retinal Detachment
Retinal detachment is the separation of the retina from its attachments to the underlying eye tissue. Symptoms of retinal detachment include flashing lights and floaters. Highly nearsighted young adults and those who've had cataract surgery are at higher risk for retinal detachment.
Tonometry
Tonometry is a method for measuring the pressure in the eye (intraocular pressure or IOP), which is useful in detecting glaucoma. IOP can be determined with the help of a tonometer, a device which lightly touches the surface of the (anesthetized) eye and measures the eye's resistance to indentation.