Myopia | definition of myopia by Medical dictionary Myopia | definition of myopia by Medical dictionary Related to myopia: hyperopia , Marketing myopia Myopia Definition Myopia is the medical term for nearsightedness. People with myopia see objects more clearly when they are close to the eye, while distant objects appear blurred or fuzzy. Reading and close-up work may be clear, but distance vision is blurry. Description To understand myopia it is necessary to have a basic knowledge of the main parts of the eye's focusing system: the cornea, the lens, and the retina. The cornea is a tough, transparent, dome-shaped tissue that covers the front of the eye (not to be confused with the white, opaque sclera). The cornea lies in front of the iris (the colored part of the eye). The lens is a transparent, double-convex structure located behind the iris. The retina is a thin membrane that lines the rear of the eyeball. Light-sensitive retinal cells convert incoming light rays into electrical signals that are sent along the optic nerve to the brain, which then interprets the images.

In people with normal vision, parallel light rays enter the eye and are bent by the cornea and lens (a process called refraction) to focus precisely on the retina, providing a crisp, clear image. In the myopic eye, the focusing power of the cornea (the major refracting structure of the eye) and the lens is too great with respect to the length of the eyeball. Light rays are bent too much, and they converge in front of the retina. This inaccuracy is called a refractive error. In other words, an overfocused fuzzy image is sent to the brain. There are many types of myopia. Some common types include: Physiologic Pathologic Acquired. By far the most common form, physiologic myopia develops in children sometime between the ages of 5-10 years and gradually progresses until the eye is fully grown. Physiologic myopia may include refractive myopia (the cornea and lens-bending properties are too strong) and axial myopia (the eyeball is too long). Pathologic myopia is a far less common abnormality.

This condition begins as physiologic myopia, but rather than stabilizing, the eye continues to enlarge at an abnormal rate (progressive myopia). This more advanced type of myopia may lead to degenerative changes in the eye (degenerative myopia). Acquired myopia occurs after infancy. This condition may be seen in association with uncontrolled diabetes and certain types of cataracts. Antihypertensive drugs and other medications can also affect the refractive power of the lens. Genetic profile Eyecare professionals have debated the role of genetics in the development of myopia for many years. Some believe that a tendency toward myopia may be inherited, but the actual disorder results from a combination of environmental and genetic factors. Environmental factors include close work; work with computer monitors or other instruments that emit some light (electron microscopes, photographic equipment, lasers, etc.); emotional stress ; and eye strain. A variety of genetic patterns for inheriting myopia have been suggested. One explanation for lack of agreement is that the genetic profile of high myopia (defined as a refractive error greater than -6 diopters) may differ from that of low myopia.

Some researchers think that high myopia is determined by genetic factors to a greater extent than low myopia. Another explanation for disagreement regarding the role of heredity in myopia is the sensitivity of the human eye to very small changes in its anatomical structure. Since even small deviations from normal structure cause significant refractive errors, it may be difficult to single out any specific genetic or environmental factor as their cause. Since 1992, genetic markers that may be associated with genes for myopia have been located on human chromosomes 1, 2, 12, and 18. There is some genetic information on the short arm of chromosome 2 in highly myopic people. Genetic information for low myopia appears to be located on the short arm of chromosome 1, but it is not known whether this information governs the structure of the eye itself or vulnerability to environmental factors. In 1998 a team of American researchers presented evidence that a gene for familial high myopia with an autosomal dominant transmission pattern could be mapped to human chromosome 18 in eight North American families. The same group also found a second locus for this form of myopia on human chromosome 12 in a large German/Italian family.

In 1999 a group of French researchers found no linkage between chromosome 18 and 32 French families with familial high myopia. These findings have been taken to indicate that more than one gene is involved in the transmission of the disorder. It has been known for some years that a family history of myopia is one of the most important risk factors for developing the condition. Only 6%-15% of children with myopia come from families in which neither parent is myopic. In families with one myopic parent, 23%-40% of the children develop myopia. If both parents are myopic, the rate rises to 33%-60% for their children. One American study found that children with two myopic parents are 6.42 times as likely to develop myopia themselves as children with only one or no myopic parents. The precise interplay of genetic and environmental factors in these family patterns, however, is not yet known. One multigenerational study of Chinese subjects indicated that subjects in the third generation had a higher risk of developing myopia even if their parents were not myopic.

The researchers concluded that, at least in China, the genetic factors in myopia have remained constant over the past three generations while the environmental factors have intensified. The increase in the percentage of people with myopia over the last 50 years in the United States has led American researchers to the same conclusion. The debate continued with more recent reports. In the summer of 2004, one report said that scientists were close to identifying the myopia gene, located on chromosome 11. Another report reviewed several studies and claimed that lifestyle was to blame for myopia. For instance, a study found that 80% of 14- to 18-year old boys studying in schools in Israel that emphasize reading religious texts have myopia, while the rates for boys in state school was just 30%. It is likely that genes and environment play a role. Myopia is the most common eye disorder in humans around the world. It affects between 25% and 35% of the adult population in the United States and the developed countries, but is thought to affect as much as 40% of the population in some parts of Asia. Some researchers have found slightly higher rates of myopia in women than in men.

The age distribution of myopia in the United States varies considerably. Five-year-olds have the lowest rate of myopia (less than 5%) of any age group. The prevalence of myopia rises among children and adolescents in school until it reaches the 25%-35% mark in the young adult population. It declines slightly in the over-45 age group; about 20% of 65-year-olds have myopia. The figure drops to 14% for Americans over 70. Myopia, or nearsightedness, is a condition of the eye in which objects are seen more clearly when close to the eye while distant objects appear blurred or fuzzy. (Illustration by Electronic Illustrators Group.) Other factors that affect the demographic distribution of myopia are income level and education. The prevalence of myopia is higher among people with above-average incomes and educational attainments. Myopia is also more prevalent among people whose work requires a great deal of close focusing, including work with computers. Causes and symptoms Myopia is said to be caused by an elongation of the eyeball.

This means that the oblong (as opposed to normal spherical) shape of the myopic eye causes the cornea and lens to focus at a point in front of the retina. A more precise explanation is that there is an inadequate correlation between the focusing power of the cornea and lens and the length of the eye. People are generally born with a small amount of hyperopia (farsightedness), but as the eye grows this decreases and myopia does not become evident until later. This change is one reason why some researchers think that myopia is an acquired rather than an inherited trait. The symptoms of myopia are blurred distance vision, eye discomfort, squinting, and eye strain. Diagnosis The diagnosis of myopia is typically made during the first several years of elementary school when a teacher notices a child having difficulty seeing the chalkboard, reading, or concentrating. The teacher or school nurse often recommends an eye examination by an ophthalmologist or optometrist. An ophthalmologist—M.D. or D.O. (Doctor of Osteopathy)—is a medical doctor trained in the diagnosis and treatment of eye problems. Ophthalmologists also perform eye surgery. An optometrist (O.D.) diagnoses and manages and/or treats eye and visual disorders.

In many states, optometrists are licensed to use diagnostic and therapeutic drugs. A patient's distance vision is tested by reading letters or numbers on a chart posted a set distance away (usually 20 ft). The doctor asks the patient to view images through a variety of lenses to obtain the best correction. The doctor also examines the inside of the eye and the retina. An instrument called a slit lamp is used to examine the cornea and lens. The eyeglass prescription is written in terms of diopters (D), which measure the degree of refractive error. Mild to moderate myopia usually falls between −1.00D and −6.00D. Normal vision is commonly referred to as 20/20 to describe the eye's focusing ability at a distance of 20 ft from an object. For example, 20/50 means that a myopic person must stand 20 ft away from an eye chart to see what a normal person can see at 50 ft. The larger the bottom number, the greater the myopia. Treatment People with myopia have three main options for treatment: eyeglasses, contact lenses, and for those who meet certain criteria, refractive eye surgery.

Eyeglasses Eyeglasses are the most common method used to correct myopia. Concave glass or plastic lenses are placed in frames in front of the eyes. The lenses are ground to the thickness and curvature specified in the eyeglass prescription. The lenses cause the light rays to diverge so that they focus further back, directly on the retina, producing clear distance vision. Contact lenses Contact lenses are a second option for treatment. Contact lenses are extremely thin round discs of plastic that are worn on the eye in front of the cornea. Although there may be some initial discomfort, most people quickly grow accustomed to contact lenses. Hard contact lenses, made from a material called PMMA, are virtually obsolete. Rigid gas permeable lenses (RGP) are made of plastic that holds its shape but allows the passage of some oxygen into the eye. Some believe that RGP lenses may halt or slow the progression of myopia because they maintain a constant, gentle pressure that flattens the cornea. As of 2001, the National Eye Institute is conducting an ongoing study of RGP lenses called the Contact Lens and Myopia Progression (CLAMP) Study, with results to be published in 2003.

A procedure called orthokeratology acts on this principle of "corneal molding." However, when contact lenses are discontinued for a period of time, the cornea will generally go back to its original shape. Rigid gas permeable lenses offer crisp, clear, sight. Soft contact lenses are made of flexible plastic and can be up to 80% water. Soft lenses offer increased comfort and the advantage of extended wear; some can be worn continuously for up to one week. While oxygen passes freely through soft lenses, bacterial contamination and other problems can occur, requiring replacement of lenses on a regular basis. It is very important to follow the cleaning and disinfecting regimens prescribed because protein and lipid buildup can occur on the lenses, causing discomfort or increasing the risk of infection. Contact lenses offer several benefits over glasses, including: better vision, less distortion, clear peripheral vision, and cosmetic appeal. In addition, contacts do not steam up from perspiration or changes in temperature. Refractive eye surgery For people who find glasses and contact lenses inconvenient or uncomfortable, and who meet selection criteria regarding age, degree of myopia, general health, etc., refractive eye surgery is a third treatment alternative.

There are three types of corrective surgeries available as of 2001: 1) radial keratotomy (RK), 2) photorefractive keratectomy (PRK), and 3) laser-assisted in-situ keratomileusis (LASIK). Refractive eye surgery improves myopic vision by permanently changing the shape of the cornea so that light rays focus properly on the retina. These procedures are performed on an outpatient basis and generally take 10-30 minutes. LASIK is approved by the FDA, though certain lasers are in various stages of approval at a given time. Patients should check with the FDA and ask for patient references when choosing a LASIK provider. RADIAL KERATOTOMY . Radial keratotomy (RK), the first of these procedures made available, has a high associated risk. It was first developed in Japan and the Soviet Union, and introduced into the United States in 1978. The surgeon uses a delicate diamond-tipped blade, a microscope, and microscopic instruments to make several spoke-like "radial" incisions in the non-viewing (peripheral) portion of the cornea.

As the incisions heal, the slits alter the curve of the cornea, making it more flat, which may improve the focus of images onto the retina. PHOTOREFRACTIVE KERATECTOMY. Photorefractive keratectomy (PRK) involves the use of a computer to measure the shape of the cornea. Using these measurements, the surgeon applies a computer-controlled laser to make modifications to the cornea. The PRK procedure flattens the cornea by vaporizing small amounts of tissue from the cornea's surface. It is important to make sure the laser being used is FDA approved. Photorefractive keratectomy can be used to treat mild to moderate forms of myopia. The cost is approximately $2,000 per eye. LASER-ASSISTED IN-SITU KERATOMILEUSIS. Laser-assisted in-situ keratomileusis (LASIK) is the newest of these procedures. It is recommended for moderate to severe cases of myopia. A variation on the PRK method, LASIK uses lasers and a cutting tool called a microkeratome to cut a circular flap on the cornea.

The flap is flipped back to expose the inner layers of the cornea. The cornea is treated with a laser to change the shape and focusing properties, then the flap is replaced. Risks All of these surgical procedures carry risks, the most serious being corneal scarring, corneal rupture, infection, cataracts, and loss of vision. In addition, a study published in March 2001 warned that mountain climbers who have had LASIK surgery should be aware of possible changes in their vision at high altitudes. The lack of oxygen at high altitudes causes temporary changes in the thickness of the cornea. Since refractive eye surgery does not guarantee 20/20 vision, it is important to have realistic expectations before choosing this treatment. In a 10-year study conducted by the National Eye Institute between 1983 and 1993, more than 50% of people with radial keratotomy gained 20/20 vision, and 85% passed a driving test (requiring 20/40 vision) after surgery, without glasses or contact lenses.

Even if the patient gains near-perfect vision, however, there are potentially irritating side effects, such as postoperative pain , poor night vision, variation in visual acuity, light sensitivity and glare, and optical distortion. Refractive eye surgeries are considered elective procedures and are not always covered by insurance plans. Myopia treatments under research include corneal implants and permanent surgically placed contact lenses. Alternative treatments Some eye care professionals recommend treatments to help improve circulation, reduce eye strain, and relax the eye muscles. It is possible that by combining exercises with changes in behavior, the progression of myopia may be slowed or prevented. Alternative treatments include: visual therapy (also referred to as vision training or eye exercises); discontinuing close work; reducing eye strain (taking a rest break during periods of prolonged near vision tasks); and wearing bifocals to decrease the need to accommodate when doing close-up work. Prognosis Glasses and contact lenses can (but not always) correct the patient's vision to 20/20. Refractive surgery can make permanent improvements for the right candidates. Key terms Accommodation — The ability of the lens to change its focus from distant to near objects.

It is achieved through the action of the ciliary muscles that change the shape of the lens. Cornea — The transparent structure of the eye over the lens that is continous with the sclera in forming the outermost, protective, layer of the eye. Diopter (D) — A unit of measure for describing refractive power. Laser-assisted in-situ keratomileusis (LASIK) — Aprocedure that uses a cutting tool and a laser to modify the cornea and correct moderate to high levels of myopia. Lens — The transparent, elastic, curved structure behind the iris (colored part of the eye) that helps focus light on the retina. Ophthalmologist — A physician specializing in the medical and surgical treatment of eye disorders. Optic nerve — A bundle of nerve fibers that carries visual messages from the retina in the form of electrical signals to the brain. Optometrist — A medical professional who examines and tests the eyes for disease and treats visual disorders by prescribing corrective lenses and/or vision therapy. In many states, optometrists are licensed to use diagnostic and therapeutic drugs to treat certain ocular diseases. Orthokeratology — A method of reshaping the cornea using a contact lens.

It is not considered a permanent method to reduce myopia. Peripheral vision — The ability to see objects that are not located directly in front of the eye. Peripheral vision allows people to see objects located on the side or edge of their field of vision. Photorefractive keratectomy (PRK) — A procedure that uses an excimer laser to make modifications to the cornea and permanently correct myopia. Radial keratotomy (RK) — A surgical procedure involving the use of a diamond-tipped blade to make several spoke-like slits in the peripheral (nonviewing) portion of the cornea to improve the focus of the eye and correct myopia by flattening the cornea. Refraction — The bending of light rays as they pass from one medium through another. Used to describe the action of the cornea and lens on light rays as they enter they eye. Also used to describe the determination and measurement of the eye's focusing system by an optometrist or ophthalmologist. Refractive eye surgery — A general term for surgical procedures that can improve or correct refractive errors by permanently changing the shape of the cornea.

Retina — The light-sensitive layer of tissue in the back of the eye that receives and transmits visual signals to the brain through the optic nerve. Visual acuity — The ability to distinguish details and shapes of objects. While the genetic factors that influence the transmission and severity of myopia cannot be changed, some environmental factors can be modified. They include reducing close work; reading and working in good light; taking frequent breaks when working at a computer or microscope for long periods of time; maintaining good nutrition ; and practicing visual therapy (when recommended). Eye strain can be prevented by using sufficient light for reading and close work, and by wearing corrective lenses as prescribed. Everyone should have regular eye examinations to see if their prescription has changed or if any other problems have developed. This is particularly important for people with high (degenerative) myopia who are at a greater risk of developing retinal detachment , retinal degeneration, glaucoma , or other problems. Resources Periodicals "Blame lifestyle for myopia, not genes." Biotech Week July 28, 2004: 65. Naiglin. L., et al.

"Familial high myopia: evidence of an autosomal dominant mode of inheritance and genetic heterogeneity." Annals of Genetics 42, no. 3 (1999): 140-146. Pacell, R, et al. "Role of genetic factors in the etiology of juvenile-onset myopia based on a longitudinal study of refractive error." Optometry and Visual Science 76 (June 1999): 381-386. Saw, SM, et al. "Myopia: gene-environment interaction." Annals of the Academy of Medicine of Singapore 29 (May 2000): 290-297. "Scientists close to identifying myopia gene." Chemistry and Industry August 16, 2004: 7. Wu, MM, and MH Edwards. "The effect of having myopic parents: an analysis of myopia in three generations." Optometry and Visual Science 76 (June 1999): 341-342. Organizations degenerative myopia See pathological myopia . early-onset myopia See acquired myopia.

false myopia See spasm of accommodation . form-deprivation myopia Myopia developing in children when the retina is stimulated by a blurred image during the critical period of development. It may occur as a result of a pathological condition, such as cataract, vitreous haemorrhage, ptosis, eyelid closure, or in inordinately long occlusion therapeutic sessions. See critical period ; occlusion therapy. high myopia Myopias above 6.0 D or more are usually considered as high myopias. See open-angle glaucoma ; high index lens; pathological myopia . hypertonic myopia See spasm of accommodation . index myopia See lenticular myopia. instrument myopia A temporary increase in accommodation induced by looking through an optical instrument. See resting state of accommodation. juvenile-onset myopia; late-onset myopia See acquired myopia. lenticular myopia Myopia attributed to an increase in the index of refraction of the lens. As a result there is an increase in refractive power. Such a change usually accompanies the development of some cataracts.

This type of myopia may also accompany or follow an increase in blood sugar level, in which case it is usually of a transient nature, i.e. the power of the crystalline lens diminishes after the blood sugar level returns to normal. Syn. index myopia. See nuclear cataract ; diabetes ; micro-spherophakia. low myopia Myopias of 3.0 D or less are usually considered as low myopias. malignant myopia See pathological myopia . medium myopia Myopias between 3.0 and 6.0 D are usually considered as medium myopias. night myopia An increase in ocular refraction (essentially accommodation) occurring at low levels of illumination. See resting state of accommodation. pathological myopia Myopia attributed to retinal and choroidal degeneration resulting from excessive elongation of the eye. The myopia usually exceeds 8-10 D, tends to increase rapidly during adolescence and continues to increase during adulthood. Visual acuity is usually subnormal after correction. Pathological myopia is a potential cause of blindness. Syn. degenerative myopia; malignant myopia; progressive myopia.

See choroideremia ; myopic crescent ; macular hole ; retinal detachment ; sclerochoroiditis ; Fuchs' spot; anterior staphyloma ; vitreous detachment . physiological myopia This is the most common type of myopia. It is believed that high myopia is due mainly to genetic factors whereas low myopia is more likely due to environmental influences. It occurs because of a failure in correlation of the refractive power of lens and cornea, and the length of the eye. Thus, the power of the eye is too great for its length. Unlike pathological myopia, this myopia usually stabilizes when the growth process has been completed. It is associated with normal visual acuity after correction. Syn. simple myopia; typical myopia. senile lenticular myopia See second sight . simple myopia See physiological myopia. space myopia An increase in accommodation occurring when viewing a field without any stimuli to accommodation as, for example, a clear sky. Syn. empty-field myopia. See resting state of accommodation. spurious myopia See spasm of accommodation . typical myopia See physiological myopia. Fig.

M16 A myopic eye looking at a distant axial point Table M10 Approximate relationship between uncorrected myopia and visual acuity Snellen visual acuity [G. fr. myo, to shut, + ōps, eye] myopia (mīō´pēə), n a form of defective vision resulting from excessive refractive power of the eye. In this condition, commonly called nearsightedness, or shortsightedness, light rays coming from an object beyond a certain distance are focused in front of the retina. myopia short sightedness; light rays focus in front of the retina. The opposite of hypermetropia. axial myopia results from the anteroposterior length of the eye being longer than normal. Patient discussion about myopia Q. Is there a laser vision correction operation that will correct both near and farsightedness? My optometrist said that typical laservision would require that I wear glasses for reading since it only corrects farsightedness. I'm leery of the technique of doing only one eye for distance and leaving the other "as is" for reading.

I seem to recall a brief news report of some new laser vision technique that corrects both near- and farsightedness. Is that true or were they referring to the "one eye for closeup and one eye for distance" type of correction that I'm skeptical about? Thanks!! A. my mother-in-law had that done about a yeara ago,for both near and far,they make them the oppisite,i had my near sightness fixed two years ago and i love it should of done it sooner..... Am I Nearsighted? Myopia Symptoms and Treatments Does It Get Better Over Time? Is it hard to see highway signs until you’re a few feet away but easy to read a book up close? Chances are you’re nearsighted . Your doctor will call this myopia . Many people see this way. Your eye doctor can fix it with eyeglasses , contacts, or eye surgery. What Causes It? The structure of your eye is to blame. When your eyeball is too long or the cornea -- the protective outer layer of your eye -- is too curved, the light that enters your eye won’t focus correctly.

Images focus in front of the retina, the light-sensitive part of your eye, instead of directly on the retina. This causes blurred vision . Doctors call this a refractive error. Symptoms Chances are the only symptom will be blurred vision at a distance. You may have also noticed: Eye fatigue when you try to see more than a few feet away Nearsighted children often have trouble reading the blackboard at school. Diagnosis and Treatment An eye exam can show you if you’re nearsighted. Glasses, contacts, or refractive surgery can correct nearsightedness. When you have myopia, your prescription for glasses or contact lenses will be a negative number. The more negative the number, the stronger your lenses will be. For example, -3.00 is stronger than -2.50. Your prescription helps the eye focus light on your retina. That clears up your vision. Eye surgery can improve your vision so much you may not ever need glasses or contacts again. The most common procedures for nearsightedness are: Photorefractive keratectomy. Also called PRK, this surgery uses a laser to sculpt the middle layer of your cornea.

That flattens the cornea’s curve and lets light rays focus closer to or on your retina. LASIK . This the most common surgery for nearsightedness. The surgeon uses a laser or another tool to create a thin flap on the top of your cornea. He surgeon sculpts the cornea with another laser and moves the flap back into place. Does It Get Better Over Time? Nearsightedness runs in families and will probably start in childhood. It stops changing after your teenage years, but not always. If you notice changes in your vision, get your eyes checked. See your eye doctor every year. WebMD Medical Reference Reviewed by Alan Kozarsky, MD on August 08, 2016 Sources Nearsightedness: What Is Myopia? - American Academy of Ophthalmology Nearsightedness: What Is Myopia? Reviewed by: Denise Satterfield MD Sep. 01, 2013 Myopia, or nearsightedness, is a refractive error, which means that the eye does not bend or refract light properly to a single focus to see images clearly. In myopia, close objects look clear but distant objects appear blurred.

Myopia is a common condition that affects an estimated 25 percent of Americans. It is an eye focusing disorder, not an eye disease. Myopia in children Myopia is inherited and is often discovered in children when they are between ages eight and 12 years old. During the teenage years, when the body grows rapidly, myopia may become worse. Between the ages of 20 and 40, there is usually little change. Myopia can also occur in adults. High myopia If the myopia is mild, it is called low myopia. Severe myopia is known as high myopia. High myopia will usually stabilize between the ages of 20-30 years old. With high myopia, you can usually correct vision easily with glasses, contact lenses or sometimes with refractive surgery. Patients with myopia have a higher risk of developing a detached retina . Ask your ophthalmologist (Eye M.D.)&nbsp;to discuss the warning signs of retinal detachment with you if you are in this risk category. If the retina does detach and it is discovered early enough, a surgical procedure can usually repair it.

It is important to have regular eye examinations by an ophthalmologist to watch for changes in the retina that might lead to retinal detachment. People with high myopia may also have a higher than average risk of developing glaucoma and cataracts . Myopia (Nearsightedness) Definition, Causes and Treatment On this page: Myopia symptoms • Myopia causes • Treatment • Myopia control • Degenerative myopia Nearsightedness, or myopia, is the most common refractive error of the eye , and it has become more prevalent in recent years. In fact, a recent study by the National Eye Institute (NEI) shows the prevalence of myopia grew from 25 percent of the U.S. population (ages 12 to 54) in 1971-1972 to a whopping 41.6 percent in 1999-2004. Though the exact cause for this increase in nearsightedness among Americans is unknown, many eye doctors feel it has something to do with eye fatigue from computer use and other extended near vision tasks, coupled with a genetic predisposition for myopia.

Watch this video on what causes blurry distance vision and how we can slow down or prevent the process. Myopia Symptoms And Signs If you are nearsighted, you typically will have difficulty reading road signs and seeing distant objects clearly, but will be able to see well for close-up tasks such as reading and computer use. Other signs and symptoms of myopia include squinting, eye strain and headaches. Feeling fatigued when driving or playing sports also can be a symptom of uncorrected nearsightedness. If you experience these signs or symptoms while wearing your glasses or contact lenses, schedule a comprehensive eye examination with your optometrist or ophthalmologist to see if you need a stronger prescription. What Causes Myopia? Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina , rather than directly on its surface. Recommended For You TheraTears contains nutrients that match your natural tears. Get $2 off! Nearsightedness also can be caused by the cornea and/or lens being too curved for the length of the eyeball.

In some cases, myopia is due to a combination of these factors. Myopia typically begins in childhood and you may have a higher risk if your parents are nearsighted. In most cases, nearsightedness stabilizes in early adulthood but sometimes it continues to progress with age. What is more important than your vision? Find local eye doctor to get an eye exam Myopia Treatment Nearsightedness can be corrected with glasses , contact lenses or refractive surgery . Depending on the degree of your myopia, you may need to wear your glasses or contact lenses all the time or only when you need very clear distance vision, like when driving, seeing a chalkboard or watching a movie. If you're nearsighted, the first number ("sphere") on your eyeglasses prescription or contact lens prescription will be preceded by a minus sign (). The higher the number, the more nearsighted you are. Vision Poll Refractive surgery can reduce or even eliminate your need for glasses or contacts. The most common procedures are performed with an excimer laser . In PRK the laser removes a layer of corneal tissue, which flattens the cornea and allows light rays to focus more accurately on the retina.

In LASIK  the most common refractive procedure  a thin flap is created on the surface of the cornea, a laser removes some corneal tissue, and then the flap is returned to its original position. Then there's orthokeratology , a non-surgical procedure where you wear special rigid gas permeable ( RGP or GP ) contact lenses at night that reshape your cornea while you sleep. When you remove the lenses in the morning, your cornea temporarily retains the new shape, so you can see clearly during the day without glasses or contact lenses. Orthokeratology and a related GP contact lens procedure called corneal refractive therapy (CRT) have been proven effective at temporarily correcting mild to moderate amounts of myopia. Both procedures are good alternatives to surgery for individuals who are too young for LASIK or are not good candidates for refractive surgery for other reasons. Implantable lenses known as phakic IOLs are another surgical option for correcting nearsightedness, particularly for individuals with high amounts of myopia or thinner-than-normal corneas that could increase their risk of complications from LASIK or other laser vision correction procedures.

Phakic IOLs work like contact lenses, except they are surgically placed within the eye and typically are permanent, which means no maintenance is needed. Unlike IOLs used in cataract surgery , phakic IOLs do not replace the eye's natural lens, which is left intact. Controlling Myopia With more and more people getting nearsighted these days, there is a lot of interest in finding ways to control the progression of myopia in childhood. Watch this video on what causes blurry vision and how we can correct it. A number of different techniques have been tried  including fitting children with bifocals , progressive lenses and gas permeable contact lenses  with mixed results. Recently, researchers in New Zealand have reported encouraging outcomes from specially designed "dual focus" soft contact lenses for myopia control in nearsighted children. The experimental lenses have significantly less power in the periphery of the lens compared to the center, and it is thought that this "peripheral defocus" may reduce the tendency for greater lengthening of the eye that leads to progressive myopia.

In a study published in 2011, the researchers found that in 70 percent of nearsighted children (ages 11 to 14) who wore the experimental lenses in one eye and a standard soft contact lens in the other, myopia progression was reduced by 30 percent or more in the eye wearing the dual focus contact lens. Though dual focus contact lenses for myopia control are not yet available in the United States, research is ongoing to evaluate the effectiveness of the lenses on a larger population of children. Degenerative Myopia In most cases, nearsightedness is simply a minor inconvenience and poses little or no risk to the health of the eye. But sometimes myopia can be so progressive and severe it is considered a degenerative condition. Try these interactive Rx forms to learn what the measurements mean on your eyeglass prescription or contact lens prescription . Degenerative myopia (also called malignant or pathological myopia) is a relatively rare condition that is believed to be hereditary and usually begins in early childhood. About 2 percent of Americans are afflicted, and degenerative myopia is a leading cause of legal blindness .

In malignant myopia, the elongation of the eyeball can occur rapidly, leading to a quick and severe progression of myopia and loss of vision. People with the condition have a significantly increased risk of retinal detachment and other degenerative changes in the back of the eye, including bleeding in the eye from abnormal blood vessel growth (neovascularization). Degenerative myopia also may increase the risk of cataracts . Surgical treatment for complications of degenerative myopia includes a combination drug and laser procedure called photodynamic therapy that also is used for the treatment of macular degeneration . Also, a recent pilot study found that an oral medicine called 7-methylxanthine (7-mx) was effective in slowing the elongation of the eye in nearsighted children ages 8 to 13. Studies of this type might eventually lead to an effective medical treatment for degenerative myopia. Nearsightedness - Mayo Clinic Nearsightedness Nearsightedness (myopia) Nearsightedness (myopia) is a common vision condition in which you can see objects near to you clearly, but objects farther away are blurry. Nearsightedness may develop gradually or rapidly, often worsening during childhood and adolescence.

Nearsightedness tends to run in families. A basic eye exam can confirm nearsightedness. You can easily correct the condition with eyeglasses or contact lenses. Another treatment option for nearsightedness is surgery. Preferred practice patterns: Refractive errors and refractive surgery summary benchmark — 2014. American Academy of Ophthalmology. Accessed Jan. 19, 2015. Myopia (nearsightedness). American Optometric Association. Accessed Jan. 19, 2015. Refractive error. The Merck Manual Professional Edition. Accessed Jan. 19, 2015. Frequency of ocular examinations — 2009. American Academy of Ophthalmology. Accessed Jan. 19, 2015. Mian SI. Visual impairment in adults: Refractive disorders and presbyopia. Accessed Jan. 19, 2015. Opticians, dispensing. U.S. Department of Labor. Accessed Jan. 19, 2015. Eye health tips. National Eye Institute. Accessed Jan. 19, 2015. Morgan IG, et al.

Myopia. The Lancet. 2012;379:1739. Myopia (adult and pediatric). AskMayoExpert. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014. Refractive error. AskMayoExpert. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015. Nearsightedness. American Academy of Opthalmology. Accessed Jan. 19, 2015. Barbara Woodward Lips Patient Education Center. Surgery to improve your vision: PRK and LASIK. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2008. Myopia (Nearsightedness). American Optometric Association. Accessed Jan. 20, 2015. Products and Services Facts About Myopia | National Eye Institute Myopia Defined What is myopia? Myopia, also known as nearsightedness, is a common type of refractive error where close objects appear clearly, but distant objects appear blurry.

When you look at an object, light rays reflect off that object and pass through the cornea and the lens of the eye, which bend (or refract) the light and focus it on the retina at the back of the eye. If you have perfect vision, the rays focus directly on the surface of the retina. But in a myopic eye, the eyeball is usually too long from front to back. This causes light rays to focus at a point in front of the retina, rather than directly on its surface. This makes distant objects blurry. Myopia can also be the result of a cornea that is too curved for the length of the eyeball or a lens that is too thick. For some people, their myopia may be caused by a combination of problems in the cornea, lens, and length of the eyeball. What are the symptoms of myopia? If you have myopia, you have trouble seeing things far away, but you can see nearby things clearly. This is why myopia is commonly called nearsightedness. If you can see well enough to read what’s on your laptop or in a book, but you struggle to see what’s on the television or a movie screen, you may be nearsighted.

Sometimes people with undiagnosed myopia will have headaches and eyestrain from struggling to clearly see things in the distance. Why does the eyeball grow too long? What causes the eyeball to grow too long isn’t completely known, but researchers are exploring a number of factors. For many people, myopia appears to be an inherited condition – in other words, if you have a parent with myopia you are at higher risk for developing it. Researchers are also looking at the effects of sex, age, ethnicity, and environmental exposures – such as sunlight and the amount of time spent doing close-up work – on the development of myopia. More recently, scientists have been considering the influence of circadian rhythms (sometimes referred to as our biological or body clock), which regulate systems in the body according to the daily cycles of light and dark, as a factor in the development of myopia. How common is myopia? Based on a study published in 2008 , experts at NIH estimate that at least 33 percent of Americans are nearsighted. According to a 2009 study , the number of Americans with myopia has increased significantly from the 1970s to the early 2000s.

The prevalence of myopia has also been increasing in many other countries around the world. It is particularly prominent among school-aged children living in urban areas in some Asian countries. In the past, people thought children might become myopic from spending too much time reading and writing, which require close-up vision, or from reading in poorly lit rooms. Recent studies suggest that the increase of myopia in children could be related to a decrease in the amount of time they spend outdoors. How is myopia diagnosed? An eye care professional can diagnose myopia during an eye exam, which usually begins with a visual acuity test. This test uses a standardized chart or card with rows of letters that decrease in size from top to bottom. Covering one eye, you will be asked to read out loud the smallest line of letters that you can see. When done, you will test the other eye. If the vision test shows that you are nearsighted, your doctor will use a retinoscope to shine light into your eyes and observe the reflection off the retina to determine the amount of refractive error you have. What kinds of treatments are available for myopia? The most common way to treat myopia is to prescribe eyeglasses or contact lenses.

Refractive surgery, once the eyes have stopped growing, has become another option for many people. To find out the amount of myopia you have, an eye care professional uses a device called a phoropter to place a series of lenses in front of your eyes until you are seeing clearly. The combination of the results from both eyes is written as a prescription that will correct your vision to make it as normal as possible. Eyeglasses use curved lenses to refocus light rays onto the retina, instead of in front of it. Contact lenses correct vision in the same way as eyeglasses, except they rest directly on the eye. Refractive surgery changes the shape of the cornea to correct myopia. There are different types of refractive surgery, but the most common are LASIK and PRK. LASIK removes tissue from the inner layers of the cornea. To do this, a section of the outer corneal surface is cut and folded back to expose the inner cornea. A laser removes a precise amount of tissue to reshape the cornea and then the flap of outer tissue is placed back in position to heal. The correction possible with LASIK is limited by the amount of corneal tissue that can be safely removed.

PRK removes a thin layer of tissue from the surface of the cornea to change its shape. This allows light to focus more accurately on the retina. Like LASIK surgery, with PRK there is a limit to how much tissue can safely be removed and the amount of nearsightedness that can be corrected. Many people will experience dry eye symptoms after refractive surgery and a small number may develop chronic dry eye syndrome. Some people may also develop vision symptoms such as double vision/ghosting, starbursts, glare, and halos, especially at night. Ask your eye doctor to discuss with you the risks and benefits of LASIK or PRK surgery before you undergo either procedure. Phakic intraocular lenses (IOLs) are a new option for people who are very nearsighted or whose corneas are too thin to allow the use of laser procedures such as LASIK and PRK. Phakic lenses are surgically placed inside the eye. What is high myopia? High myopia is a severe form of myopia in which the eyeball continues to grow and becomes very long from front to back. It can increase the risk for retinal detachment , early development of cataracts and glaucoma .

What is degenerative myopia? Degenerative myopia (also called pathological or malignant myopia) is a rare and mostly inherited type of myopia that begins in early childhood. In degenerative myopia, the eyeball elongates rapidly and causes severe myopia, usually by the teenage or early adult years. Degenerative myopia may also progress far into the adult years. People with the condition have a significantly increased risk of retinal detachment and other degenerative changes in the back of the eye, including choroid neovascularization (abnormal blood vessel growth), and glaucoma. What research is being done? From 1996-2013 the COMET (Correction of Myopia Evaluation Trial) made many contributions to our understanding of why myopia develops and how it can be treated. One of the most recent COMET reports, published in 2014, looked at seasonal differences in how quickly myopia progresses in young children. The Pediatric Eye Disease (PED) Consortium is a recently funded project that brings together all existing population-based studies of eye diseases among preschool children around the world.

It creates a repository of population-based survey data on vision health among more than 17,000 children between the ages of six and 72 months. PED Consortium researchers are using the data to look for demographic, behavioral, and clinical factors associated with the development of moderate to severe refractive errors. A number of NEI-funded studies are investigating how natural light exposure and daily circadian rhythm patterns influence the development of the eyeball. These studies are especially important since abnormal growth in the length of the eyeball is what causes myopia. Early studies with animal models have shown that environments that exclude natural daylight, or are solely lit by artificial light, or that switch day for night, influence how long the eyeball grows. Better understanding of the relationship between circadian rhythms and light exposure could provide new ways to decrease the risk for developing myopia. NEI-supported researchers are also exploring the genetic causes of degenerative myopia. One study is working with members of a large, extended family, many of whom have degenerative myopia. The researchers are using genetic linkage analysis to identify possible causative genes, and then exploring what these genes do in eye tissue. Understanding the underlying mechanisms of degenerative myopia will help scientists work toward better treatments.

LASIK has become a popular surgical method to correct myopia in the United States, but not much is known about the long term outcomes of LASIK surgery. In October of 2009, the U.S. Food and Drug Administration (FDA), the National Eye Institute (NEI), and the Department of Defense (DOD) launched a collaborative study to look at how people fared after LASIK surgery. These studies – Patient Related Outcomes with LASIK (PROWL I and II) laid the groundwork for a computer based questionnaire used to assess how many, of a select group of people who all received the same standardized LASIK treatment, experienced significant problems such as dry eye or vision irregularities (double vision, haloing, starbursts, or glare) over a period of 3 months following the procedure. The data gathered from this survey will give us a much better idea of the long term risks and benefits of LASIK. Last Reviewed: Myopia: Learn the Definition, Causes and Control 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. Nearsightedness, Farsightedness and Astigmatism Home > Wilmer Eye Institute > Conditions Nearsightedness, Farsightedness and Astigmatism Nearsightedness (myopia) is a very common condition in which the light coming into the eye is not focused properly onto the retina, making it difficult to see objects far away. The condition is usually caused by an elongation of the eyeball that occurs over time. Farsightedness (hyperopia) is the opposite of myopia, and is usually caused by shortening of the eyeball. Astigmatism is an imperfection of the cornea preventing part of it from focusing light onto the retina. The result is a blurred area within an otherwise clear image. This problem may occur along with either myopia or hyperopia. These frequent conditions are termed "refractive errors." Diagnosis: The common method of measuring vision loss is the Snellen Test Chart, the familiar rows of increasingly smaller letters.

Wilmer ophthalmologists also diagnose a decline in vision using refraction and retinoscopy and, when necessary, automated computerized devices. Treatment: Wilmer optometrists and ophthalmologists prescribe eyeglasses and contact lenses to compensate for most refractive errors. In addition, newer techniques actually change the curved shape of the cornea, causing it to focus light directly onto the retina, thus producing a clear image. The techniques performed at Wilmer include Automated Lamellar Keratectomy (ALK), Radial Keratotomy (RK), Excimer Laser Photo Refractive Keratectomy (PRK), and LASIK - a combination of ALK and excimer laser surgery currently undergoing investigation. Wilmer physicians participated in the development of the excimer laser, which they have used since 1990. With it, Wilmer physicians can remove a thin layer of the cornea to sculpt its shape to reduce or correct the refractive error. This new technique is approved for persons 18 years of age and older with specified types of nearsightedness.

In RK, the surgeon makes a series of incisions in the cornea, producing a spokelike pattern of cuts that flattens the tissue, causing light to be focused on the retina instead of in front of it. A 10-year, multicenter study of RK found that it safely and effectively reduces a person's dependence on eyeglasses or contact lenses. Nearsightedness (Myopia)-Topic Overview Nearsightedness (Myopia) Credits What is nearsightedness? Nearsightedness (myopia) is a common cause of blurred vision . It can be mild, moderate, or severe. If you are nearsighted, objects in the distance appear blurry and out of focus. You might squint or frown when trying to see distant objects clearly. View a photo as seen through a normal and a nearsighted eye . Nearsightedness is usually a variation from normal, not a disease. Less often, nearsightedness happens because of another disease or condition. What causes nearsightedness? Most nearsightedness is caused by a natural change in the shape of the eyeball. Less often, nearsightedness may be caused by a change in the cornea or the lens .

These problems cause light rays entering the eye to focus in front of the retina . Normally, light focuses directly on the retina . What are the symptoms? The main symptom is blurred vision when looking at distant objects. If you can see well enough to read newspaper print but you struggle to see things that are farther away, you are probably nearsighted. You may have trouble clearly seeing images or words on a blackboard, movie screen, or television. This can lead to poor school, athletic, or work performance. Your child may be nearsighted if he or she squints or frowns, gets headaches often, or holds books or other objects very close to his or her face. Children who are nearsighted may sit at the front of the classroom or very close to the TV or movie screen. They may not be interested in sports or other activities that require good distance vision . If you think that your child may be nearsighted, see an eye care specialist. Treating nearsightedness early is important. With better visual skills, your child won't have as much trouble doing school work and other activities that require a person to see things far away. When does nearsightedness start? How does it change over time?

Nearsightedness usually begins in childhood between ages 6 and 12. During the teen years, as the eyeballs continue to grow, it may develop or get worse quickly. Teenagers may need new glasses every 12 months or even more often. Nearsightedness usually stops getting worse by age 20. Most nearsightedness stabilizes at a mild to moderate level. Continued How is nearsightedness diagnosed? A routine eye exam can show whether you are nearsighted. The eye exam includes questions about your eyesight and a physical exam of your eyes . Ophthalmoscopy , slit lamp exams, and other tests that check vision and eye health are also part of a routine eye exam. Eye exams should be done for new babies and at all well-child visits. 1 Nearsightedness is usually first discovered in children of grade-school age. How is it treated? Most people who are nearsighted use eyeglasses or contact lenses to correct their vision. Surgery can also reduce or fix nearsightedness. There are several surgery options, such as LASIK , PRK (photorefractive keratectomy), and artificial lens implants.

The goal of surgery is to help you see more clearly without glasses or contacts. Most doctors consider 20/40 vision or better after surgery a satisfactory result. People with 20/40 vision or better are allowed to drive a car without corrective lenses. If glasses or contact lenses are inconvenient for your work or lifestyle, surgery may be a good choice. But nearsightedness is not a disease, and a nearsighted eye is otherwise normal and healthy. Weigh your desire to have clear vision without glasses or contacts against the risks and cost of surgery. And be aware that you may still need to wear glasses or contact lenses after surgery. If your vision doesn't bother you and if you have no driving problems or other safety concerns, you don't need to have any treatment. Nearsightedness won't affect the health of your eye, and it won't get worse just because you don't wear glasses or don't have surgery. If you are nearsighted, get regular eye exams, and see your eye care specialist if you have changes in your vision. WebMD Medical Reference from Healthwise This information is not intended to replace the advice of a doctor.

Healthwise disclaims any liability for the decisions you make based on this information.© 1995-2015 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. Pagination Myopia (Nearsightedness) Myopia (Nearsightedness) How is myopia treated? Nearsightedness, or myopia, as it is medically termed, is a vision condition in which people can see close objects clearly, but objects farther away appear blurred. People with myopia can have difficulty clearly seeing a movie or TV screen or the whiteboard in school. Myopia occurs if the eyeball is too long or the cornea (the clear front cover of the eye) is too curved. As a result, the light entering the eye isn't focused correctly, and distant objects look blurred. Myopia affects nearly 30 percent of the U.S. population. While the exact cause of myopia is unknown, there is significant evidence that many people inherit myopia, or at least the tendency to develop myopia. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted.

Even though the tendency to develop myopia may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop myopia. Generally, myopia first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. However, myopia may also develop in adults due to visual stress or health conditions such as diabetes. Myopia may also occur due to environmental factors or other health problems: Some people may experience blurred distance vision only at night. With "night myopia," low light makes it difficult for the eyes to focus properly. Or the increased pupil size during dark conditions allows more peripheral, unfocused light rays to enter the eye. People who do an excessive amount of near-vision work may experience a false or "pseudo" myopia. Their blurred distance vision is caused by overuse of the eyes' focusing mechanism. After long periods of near work, their eyes are unable to refocus to see clearly in the distance. Clear distance vision usually returns after resting the eyes.

However, constant visual stress may lead to a permanent reduction in distance vision over time. Symptoms of myopia may also be a sign of variations in blood sugar levels in people with diabetes or may be an early indication of a developing cataract. An optometrist can determine the cause of the vision problems through a comprehensive eye exam . How is myopia diagnosed? Testing for myopia may use several procedures to measure how the eyes focus light and to determine the power of any optical lenses needed to correct the reduced vision. As part of the testing, you will identify letters on a distance chart. This test measures visual acuity , which is written as a fraction, such as 20/40. The top number of the fraction is the standard distance at which testing is performed (20 feet). The bottom number is the smallest letter size read. A person with 20/40 visual acuity would have to get within 20 feet to identify a letter that could be seen clearly at 40 feet in a "normal" eye. Normal distance visual acuity is 20/20, although many people have 20/15 (better) vision.

Using an instrument called a phoropter, an optometrist places a series of lenses in front of your eyes and measures how they focus light using a handheld lighted instrument called a retinoscope. Or the doctor may choose to use an automated instrument that evaluates the focusing power of the eye. The power is then refined based on your responses to determine the lenses that allow the clearest vision. Your optometrist can conduct this testing without using eye drops to determine how the eyes respond under normal seeing conditions. In some cases, such as for patients who can't respond verbally or when some of the eye's focusing power may be hidden, an optometrist may use eye drops. The eye drops temporarily keep the eyes from changing focus during testing. Using the information from these tests, along with the results of other tests of eye focusing and eye teaming, your optometrist can determine if you have myopia. He or she will also determine the power of any lens correction needed to provide clear vision. Once testing is complete, your optometrist can discuss treatment options. How is myopia treated? People with myopia have several options available to regain clear distance vision. They include: Eyeglasses.

For most people with myopia, eyeglasses are the primary choice for correction. Depending on the amount of myopia, you may only need to wear glasses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, you may need to wear them all the time. Generally, a single-vision lens is prescribed to provide clear vision at all distances. However, patients over age 40, or children and adults whose myopia is due to the stress of near-vision work, may need a bifocal or progressive addition lens. These multifocal lenses provide different powers or strengths throughout the lens to allow for clear vision in the distance and up close. Contact lenses. For some individuals, contact lenses offer clearer vision and a wider field of view than eyeglasses. However, since contact lenses are worn directly on the eyes, they require proper care to safeguard eye health. Ortho-k or CRT. Another option for treating myopia is orthokeratology (ortho-k) , also known as corneal refractive therapy (CRT). In this nonsurgical procedure, you wear a series of specially designed rigid contact lenses to gradually reshape the curvature of your cornea, the front outer surface of the eye.

The lenses place pressure on the cornea to flatten it. This changes how light entering the eye is focused. You wear the contact lenses for limited periods, such as overnight, and then remove them. People with moderate myopia may be able to temporarily obtain clear vision for most of their daily activities. Laser procedures. Laser procedures such as LASIK (laser in situ keratomileusis) or PRK (photorefractive keratectomy) are also possible treatment options for myopia in adults. A laser beam of light reshapes the cornea by removing a small amount of eye tissue. The amount of myopia that PRK or LASIK can correct is limited by the amount of corneal tissue that can be safely removed. In PRK, a laser removes a thin layer of tissue from the surface of the cornea in order to change its shape and refocus light entering the eye. LASIK removes tissue from the inner layers, but not from the surface, of the cornea. To do this, a section of the outer corneal surface is lifted and folded back to expose the inner tissue. A laser then removes the precise amount of corneal tissue needed to reshape the eye.

Then, the flap of outer tissue is placed back in position to heal. Other refractive surgery procedures. People who are highly nearsighted or whose corneas are too thin for laser procedures may be able to have their myopia surgically corrected. An optometrist may be able to implant small lenses with the desired optical correction in their eyes. The implant can be placed just in front of the natural lens (phakic intraocular lens implant), or the implant can replace the natural lens (clear lens extraction with intraocular lens implantation). This clear lens extraction procedure is similar to cataract surgery but occurs before a cataract is present. Vision therapy for people with stress-related myopia. Vision therapy is an option for people whose blurred distance vision is caused by a spasm of the muscles that control eye focusing. Various eye exercises can improve poor eye focusing ability and regain clear distance vision. If you have myopia, you have a variety of options to correct your vision problem. In consultation with your optometrist, you can select the treatment that best meets your visual and lifestyle needs. Get Connected Twitter Spots and Floaters: what are they, what causes them, and are they a symptom of an underlying issue? 6 hours ago

Question: What is the common name for the condition of myopia?
Answer: Shortsightedness