Eyes are one of the important human organs that allows you to see the world. In medicine there are many various diseases visual apparatus, one of which is refractive error. Refraction is the process of refraction of light, which affects the quality of human vision. When it is violated, a number of signs and diseases of the visual apparatus arise.
Types of violation
There are several types of eye refraction, each of which has certain characteristics, characteristic symptoms and changes.
Emmetropia
Patients experience decreased image clarity. Characterized by improper refraction or focusing of light. The rays do not hit the retina, but pass nearby.
Thus, the main sign of pathology is the unclearness and vagueness of the picture. May be accompanied by headaches when overexerting muscle tissue visual apparatus.
Myopia
The condition is known as myopia. It appears in the form of a display of the resulting image not on the retina, but in front of it.
In medicine, there are three degrees of pathology: weak, medium and high. They differ in the severity of the signs and the degree of distortion of the picture.
Hypermetropia
Also called farsightedness. With the disease, the retina is not able to clearly perceive the resulting image near or far. Just like farsightedness, the pathology has three stages of development:
- Weak. The refractive power changes as a result of an increase or decrease in the tension of the lens. However, the patient is not always recommended to wear glasses. The violation does not exceed +2 diopters.
- Average. Glasses are used when working with objects that are located fairly close. The violation is +5 diopters.
- High. Glasses should always be worn, regardless of the work performed. Based on research results, it has been established that all newborns have this degree of impairment. This is explained by the fact that the lens is not sufficiently developed, and the eyeball does not have large sizes. As it grows, the disorder disappears.
The degree of change is determined based on diagnostic studies. The need to wear glasses is determined by the attending physician.
Presbyopia
The disease is observed in elderly patients, which is why it is called senile farsightedness.
Pathology occurs as a result of the fact that over time the lens loses mobility and flexibility. The process of focusing on certain subjects is difficult.
For you!
Presbyopia is fraught not only with visual impairment, but also with frequent headaches. Patients complain about headache, feeling of tension and tightness in the eye area. There are methods to relieve the intensity of pain not only with medication, but with the help of massage, oils and other things.
Anisometry
A disease of the visual apparatus, which is characterized by damage to only one eye.
Refraction can only be set on one. The second eye has no abnormalities.
Astigmatism
The pathology is characterized by an irregular shape of the entire eye, lens or cornea. As a result, a person’s vision is significantly reduced and the picture is blurred.
The change cannot be completely compensated even with the use of special glasses. Lack of therapy leads to strabismus and sharp decline quality of vision.
Reasons for violation
Refractive error in one eye or both eyes occurs for certain reasons. Violations are often provoked by external factors. But congenital anomalies can also increase the risk of developing the disease.
For you: Hypertensive type retinal angiopathy
Experts highlight following reasons refractive errors
- Predisposition. If one parent has pathology, the chance of the child developing the disease is about 55%.
- Regular eye strain. Occurs when watching TV for a long time, working at the computer every day.
- Incorrect correction in the presence of refractive error. Occurs when wearing low-quality lenses or glasses.
- Damage to the eyeball or other organs of vision. These include traumatic changes and a thinned cornea.
- Previously performed surgical interventions.
Refractive error occurs in children adolescence or premature newborns.
Diagnostic methods
In order to establish accurate diagnosis the specialist prescribes a series diagnostic measures. First of all, the ophthalmologist examines the medical history and determines the existing symptoms. Also prescribed:
Based on the results obtained, the specialist makes a diagnosis and prescribes a course of therapy.
Treatment
Refractive error is corrected through correction, which is carried out using several methods:
- Glasses. Depending on the type and degree of impairment, you need to wear them all the time or only when working with small objects, reading a book, or watching TV. The lenses are selected by an ophthalmologist based on the severity of the disease.
- Contact lenses. They are most often used only during the daytime, but can be worn constantly. They are also selected by the attending physician.
- Laser correction. When severe violation refraction shown surgical intervention. The operation is performed using a laser.
The choice of correction method is made by the attending physician depending on the degree and severity of the disorder.
Possible complications
Decreased quality of vision in the absence timely treatment may cause serious consequences. That is why you should not hesitate to go to the doctor.
The optical system of the organ of vision refracts light rays when they hit the retina. This phenomenon is called refraction of the eye. The path of transformation of light beams is complex and takes place in several stages.
Refractive process
The process involves the cornea, lens, vitreous. Physiological parameters are maintained with the help of moisture in the anterior chamber of the eye. On its way to the brain, the light beam is refracted when it encounters each structure. Its speed, direction, frequency changes. These indicators depend on the refractive properties of each individual medium.
The light flux goes through 4 stages of refraction: at the anterior and posterior borders of the cornea, then at the same parts of the lens. Then it is projected onto the retina.
The optical system of the human eye has a refractive power of 59.92 D at long distance and 70.5 D at near distance.
The focusing of rays on the retina depends not only on the strength, but also on the length of the axis of the eye. On average, its length is 25.3 mm.
After all the stages of refraction of light rays, an image is projected onto the retina, rotated 180° (upside down), significantly reduced, and unfolded in a mirror image (from right to left).
The optical system of the organ of vision has a specific property - accommodation, the ability to change refraction. For example, in order to obtain a clearer image of an object, the curvature of the lens involuntarily changes.
Kinds
Refraction is physical and clinical.
Physical form is the very power of refraction of a light ray. But this is not enough for a person to see a clear picture; the correct focus of the rays on the retina is also necessary. These two properties together are called clinical refraction. This is the term used in ophthalmology when researching and treating patients.
Emmetropic
Emmetropia is a normal, physiological refraction. The main focus is the point of intersection of the retina and the rays. They pass all biological lenses. On the retina, light is converted into excitation waves, which travel along the nerve fiber to the brain. There an image is created with all the objects and colors.
A person with emmetropic refraction sees all objects with maximum clarity and distinguishes details. His vision is said to be 100%. People with emmetropia do not need correction with glasses or contact lenses.
Ametropic
Ametropia refers to disproportionate refraction clinical form. Parallel light streams are focused not on the retina itself, but in front or behind it. Ametropic refraction includes any visual impairment.
Myopia - the posterior point of refraction of rays is located in front of the retina. The eye distinguishes things well at a close distance, objects in the distance blur before the eyes, their clear outlines are not visible.
There are 3 degrees of severity of this type of refraction:
- weak – up to 3 D;
- average – from 3 to 6 D;
- high – more than 6 D.
With mild myopia, there is no need to wear glasses all the time. A person sees everything up close, can read, write, and work on a computer. Glasses are only worn to watch TV.
Farsightedness – light rays are focused behind the retina. In 90% of cases, patients simultaneously have poor vision near and at long distances. A person gets tired when doing work that requires eye strain - driving a car, assembling parts, sewing, printing on a computer.
Severity of farsightedness:
- weak - the lens will retain the ability to change its curvature, the condition does not need correction;
- medium – there is a need to use glasses while reading;
- high – a person constantly wears glasses to correct near and far vision.
All newborns experience physiological farsightedness, which is normal. This is a natural process of development of the organ of vision. In infants, due to the small volume of the eyeball, there is a small axis between the extreme anterior and posterior points of refraction of the rays. As the child grows, this distance increases and farsightedness goes away on its own.
Age-related farsightedness, or presbyopia, is a pathology that develops against the background of a decrease in the elasticity of the lens (in older people, metabolic and regeneration processes slow down, and degenerative transformations are triggered). The physiological ability of the lens to change its curvature is lost. At the same time, the muscular system of the eyes weakens. The risk group includes all people over 40–45 years of age.
Anisometropia is a combination various violations refraction in one patient. There are differences in the degree of myopia or farsightedness in each individual eye, or myopia on the one hand, and hyperopia on the other.
Astigmatism - more common congenital pathology vision. Several focusing rays are formed on the retina at once. Appears in one eye varying degrees refraction. This condition can only be corrected with glasses, toric or astigmatic lenses. 
Causes of refractive errors
The exact reasons why refraction is impaired have not been established. There are factors that indirectly or directly affect the development of pathological vision:
- Hereditary predisposition. If parents have a refractive error, then with a 50% chance the child will have vision problems.
- Improper organization of working time, which leads to regular eye strain (continuous use of a computer, driving a car at long distances at night, working with small parts in poor general lighting).
- Incorrectly selected glasses or lenses for vision correction.
- Violation anatomical structures eyes, changes in the length of the axis along which light beams are refracted, impaired refraction of optical media due to loss of transparency of the cornea, thinning of the lens, tissue infiltration. This is due to age-related changes.
- Mechanical eye injuries: bruises, ruptures, burns of various etiologies, contusion.
- In children - prematurity, low birth weight, vitamin deficiencies, birth trauma.
- Microsurgical treatment of the organ of vision.
Symptoms of eye refractive error
Signs of refractive error are a decrease in the quality of vision. The clarity of visible objects disappears, the boundaries of objects blur. Spots, third-party images, and spots appear before the eyes.
The condition of the eyes may vary depending on the time of day. In the evening, when the eyes get tired, physical symptoms may appear:
- general weakness;
- pain in the eye socket with any attempt to strain vision;
- cutting, stabbing sensations, visual discomfort.
Diagnostic features
Diagnostic measures begin with collecting anamnesis. They identify all the patient’s complaints, the timing of the first signs of refractive error, determine the likelihood of the influence of heredity, whether there have been head injuries, or whether eye surgery has been performed.
Instrumental methods help to reliably diagnose the condition of the optical system:
- Visometry is a method of determining the degree of visual acuity using special tables. They depict letters that become smaller in size with each line. If vision is excellent, the eye sees the lowest line from a distance of 5 m. For children, tables with pictures or rings are used, where you need to show the direction of the ring break.
- Hardware refractometry is an automated method for detecting changes in refraction. During the examination, the patient places his chin on a special notch, the doctor directs infrared radiation to his retina and evaluates the organ of vision.
- Ophthalmometry - measures the refractive power and degree of curvature of the lens, the outer transparent membrane.
- Cycloplegia - blockade eye muscles using medicines to detect false myopia. During the examination, all patients showed myopia. After the drug is eliminated from the body, vision returns to normal. If present residual effects and myopia does not improve, refractive error should be suspected.
Other methods of examining the organ of vision:
Treatment
The main direction of treatment for pathological refraction is vision correction with glasses or lenses. The choice is made taking into account the severity of the altered optical system of the eye.
Lenses prescribed to correct refractive error are either continuous (extended), which can be worn for a month, or daytime (flexible), which are removed before bedtime.
Modern and effective method vision restoration – laser correction. Using enhanced light radiation, they reduce the thickness of the transparent shell, thereby improving its refractive ability.
Refractive surgery for vision correction is aimed at eliminating myopia, farsightedness, and astigmatism of any severity.
With age, all people are at risk of decreased visual acuity. If the problem is identified and monitored in a timely manner, vision can be completely restored.
Poor prognosis in people with malignant tumors, eye injuries, cranial nerves when irreversible processes occur in the body and it is impossible to completely restore vision.
As if through wires, it is transmitted to the brain. The image will be clear if the cornea and lens refract the rays so that the focus (the point of connection of the rays) is on the retina. This is why healthy people see well into the distance.
Myopia (myopia)
Myopia (myopia) is a visual impairment in which a person sees objects located nearby well, but objects distant from him - poorly. Unfortunately, myopia is very common, affecting both children and adults. According to WHO, 800 million people on the planet suffer from myopia. With myopia, the rays of light are focused in front of the retina, and the image turns out blurry.
This can happen for two reasons: the cornea and lens refract light rays too much; As the eye grows, it lengthens excessively and the retina moves away from its normally located focus. The normal length of an adult eye is 23-24 mm, and with myopia it reaches 30 mm or more. Each millimeter lengthening of the eye leads to an increase in myopia by 3 diopters.
There are three degrees of myopia:
- low degree of myopia - up to 3 diopters;
- average degree - from 3 to 6 diopters;
- high myopia - over 6 diopters.
Why does myopia develop?
There are many reasons causing myopia. But doctors consider the following to be the main ones: prolonged visual stress at close range (excessive visual work without rest, in poor lighting); hereditary predisposition; peculiarities of the structure of the eyeball and metabolism in it; weakened sclera that does not provide adequate resistance excessive growth eyes; insufficiently developed accommodative muscle of the eye, which is responsible for “tuning” the lens to different distances; Overexertion of a weakened muscle can also lead to myopia.
Symptoms of myopia
As a rule, myopia develops already in childhood and becomes quite noticeable in school years. Children begin to see distant objects worse, have difficulty distinguishing letters and numbers written on the blackboard, and try to sit closer to the TV or in the front rows of the cinema. When trying to look at distant objects, nearsighted people often squint their eyes. In addition to deterioration of distance vision, myopia also affects vision at dusk: in evening time Myopic people find it difficult to navigate on the street and drive a car. To improve vision, nearsighted people are forced to wear contact lenses or points with a minus value. Often they need to frequently change glasses and lenses due to deteriorating vision. However, you should know that glasses cannot stop the development of myopia; they only correct the refraction of light. If vision deteriorates and you have to change your glasses to stronger ones, it means that myopia is progressing. This occurs due to increasing stretching of the eyeball.
Progressive myopia
Progressive myopia is not a harmless vision defect that can be corrected with glasses, but a serious eye disease with serious consequences. Progressive myopia usually affects children aged 7-15 years. Stretching of the eyeball leads to the fact that the vessels inside the eye lengthen, the nutrition of the retina is disrupted, and visual acuity decreases. The retina, like a stretched delicate veil, “creeps” in places, holes appear in it and, as a result, retinal detachment may occur. Exactly this severe complication myopia, in which vision is significantly reduced, up to complete blindness.
Remember! A timely visit to an ophthalmologist will help you prevent dangerous complications of myopia and save your vision!
Diagnostics
Only a specialist can determine the degree of your myopia and choose the most suitable one for you. this case treatment method .
The clinic's doctors will conduct the necessary examination using high-precision equipment. Diagnosis of myopia includes the following studies:
- checking distance visual acuity without glasses, selecting the glasses you need;
- determination of the refraction (refraction) of your eyes and the degree of myopia;
- measuring eye length in the office ultrasound diagnostics. This is a painless and very accurate study; based on its results, the doctor judges the progression of myopia;
- measuring the thickness of the cornea at various points using ultrasound. This test is necessary if you are having refractive surgery;
- examination of the fundus (ophthalmoscopy), which will allow the doctor to assess the condition of the retina, blood vessels, optic nerve each eye.
This is a general scheme for examining patients with myopia, but the treatment of each person requires individual approach. Therefore, if necessary, the doctor may prescribe additional tests for you.
Treatment
Doctors identify the following main areas of treatment for myopia:
- stopping pathological eye growth;
- warning possible complications myopia;
- correction of the refraction of a myopic eye, eliminating, if possible, wearing glasses and contact lenses.
Farsightedness (hypermetropia)
Farsightedness or hypermetropia is a refractive error in which patients have reduced visual acuity when looking at objects up close. However, with high degree of farsightedness, the patient has difficulty distinguishing objects located from him either at a distance of 20-30 cm or further than 10 m. Farsightedness leads to systematic overstrain of the eye muscles, so people suffering from hypermetropia often suffer from headaches and visual fatigue. On average, approximately every second inhabitant of the Earth over 30 years of age suffers from farsightedness to one degree or another. Before the age of six and after 50, farsightedness is natural state human visual apparatus. Normally, in a person with good vision, the image is focused in the central zone of the retina, while with farsightedness, the image is formed on the plane behind it.
Causes of farsightedness
The main cause of abnormal eye refraction is most often the small size of the eyeball in the anteroposterior direction. This is why farsightedness is natural in newborn children. physiological phenomenon, which in most cases goes away on its own with age. Also, the cause of farsightedness is a violation of the accommodation of the lens, its inability to correctly change the curvature. This disorder also leads to the development of age-related farsightedness or presbyopia, that is, a decrease in the accommodative capabilities of the lens of the eye with age, which is manifested by a decrease in the clarity of images of nearby objects and difficulty in reading.
There are three degrees of hypermetropia:
- weak degree - up to 4 diopters;
- average degree - from 4 to 8 diopters;
- high degree of farsightedness - over 8 diopters.
Treatment of farsightedness
Treatment of hypermetropia consists of spectacle, contact, or surgical correction.
Astigmatism
Astigmatism is one of the most common refractive errors.
Causes of astigmatism
Astigmatism occurs due to the nonspherical shape of the cornea, and less commonly, the lens. In normal condition, the cornea and lens of a healthy eye have a smooth, spherical refractive surface. With astigmatism, the sphericity of the cornea and lens is disrupted and has different curvature in different meridians. Accordingly, astigmatism is a condition in which different meridians of the surface of the cornea have different refractive powers and the image of an object when light rays pass through such a cornea is distorted. Some areas of the image are focused on the retina, others are “behind” or “in front” of it. Consequently, instead of a normal image, a person sees a distorted one, in which some lines are sharp and others are blurred. A similar image can be obtained if you look at your distorted reflection in an oval teaspoon. This distorted image is formed on the retina of the eye in the presence of astigmatism.
Astigmatism, depending on the refraction of the eye, can be:
- myopic,
- hypermetropic,
- mixed.
There are three degrees of astigmatism:
- weak - up to 2 diopters;
- medium - up to 3 diopters;
- high degree astigmatism - 4 or more diopters.
Treatment of astigmatism
Astigmatism is treated with glasses or contact correction, or surgically.
False myopia is what spasm of accommodation is called. In common parlance, this pathology is called “tired eyes syndrome.” As a rule, it occurs in adolescents of preschool and school age.
Caused by heavy strain on the eyes: knitting, sewing, jewelry making, spending a lot of time looking at the monitor.
Externally, the disease is very similar to myopia, the eyes become very tired, farsightedness worsens, and may be accompanied by pain syndromes eye area.
Why is this happening? If we consider the work of the eye, it can be compared with the work of binoculars, where the role of the wheel for focusing the image is played by the lens, which moves with the help of a muscle and selects the correct distance and focus for viewing.
If the object is at a distance, the muscle, called the ciliary muscle, relaxes, allowing the lens to take a flat shape. When viewing objects at close range, the muscle contracts and the lens takes on a convex shape.
If such tension lasts for a long time, then vision deteriorates, this is explained by the “fatigue” of the ciliary muscle. Therefore, the eye is deprived of the ability to react to changes in focus.
Accommodation spasm is a decrease in vision as a result of prolonged overexertion or fatigue. A person develops false myopia, which can develop into real myopia, and as a result, myopia.
Comments
In a healthy eye, the cornea and lens have a regular hemispherical shape.
Light passing through them is refracted equally in horizontal and vertical planes.
With astigmatism, the irregular shape of the lens or cornea leads to focusing problems.
A ray of light refracted in the eye is not collected at one point on the surface of the retina, as in the eye healthy person, but is scattered over several, behind or in front of the retina.
As a result, the eye cannot focus on objects in the field of view, and the image appears blurry.
In most cases, astigmatism is asymmetrical, which makes it difficult to select means for its correction. In addition, very often it is accompanied by other eye diseases: from microphthalmos to myopia.
Comments
About a quarter of the entire population of the planet is faced with a problem that everyone knows as farsightedness.
Another more scientific name is hypermetropia. This is a vision disorder in which the image is focused behind the retina rather than on it.
To obtain a clear image, it is necessary to increase refraction, and for this you need to strain your eyes.
This is why most people with farsightedness quickly get tired and experience headaches when working at a computer or with documents.
There is a misconception that farsighted people see well in the distance and see poorly near. In fact, they may have difficulty seeing distant objects.
Comments
Often, among acquaintances or simply in a crowd of passers-by, you can meet a person whose strabismus is noticeable to others.
The reason for this may be astigmatism - a congenital or acquired pathology of the cornea or lens.
Correction of astigmatism is more productive on early stages disease, the choice of treatment depends not only on the stage of visual impairment, but also on the causes leading to impaired visual function.
Comments
There are several deviations in vision that make it difficult to clearly and in detail distinguish objects at close or far distances.
Refractive errors (ametropia) are a group pathological conditions characterized by impaired focusing of light rays on the retina and decreased quality of vision. Refractive errors of the visual organs include myopia, farsightedness, etc. All these conditions are accompanied fatigue eye, painful sensations, blurred vision and others common features. Treatment of ametropia is usually conservative.
Refraction of the eye - what is it? This is the ability of the organs of vision to refract light rays striking the retina. The optical system of the visual apparatus has a complex structure and consists of several parts:
- cornea;
- lens;
- vitreous body;
- chamber moisture.
With normal refraction and accommodation of the eyes, which is also called, light rays passing through the lens system intersect at the focus of the retina, thanks to which a person sees a clear image. In a healthy person, the focal length is 23-25 mm, and the refractive power of the eye is 60 diopters. Sometimes by various reasons refracted light rays converge not at the retinal focus, but in front or behind it. This phenomenon is considered a violation of accommodation and refraction and requires treatment.
Causes
Refractive errors are common and can occur at any age. There are many etiological factors, provoking the development of ametropia, but in many cases it is not possible to determine the cause. The following are the main causes of refractive errors:
- Genetic predisposition. If at least one of the parents has a refractive error, then there is high risk development of problems in children.
- Violation anatomical structure eye: deviation from the norm of the axis of the eyeball, clouding of the lens, disturbance of accommodation.
- Excessive strain on the eyes: prolonged reading, working at a computer or watching TV.
- Injuries to the visual apparatus.
- Infectious and inflammatory diseases: rubella, congenital toxoplasmosis.
- Metabolic disorder. When material metabolism is disrupted, the risk of changes in accommodation increases. People with diabetes are most susceptible to developing ametropia.
- Lack of timely treatment of existing ophthalmological diseases.
- Surgical intervention on the organs of vision.
The likelihood of refractive error increases with an unhealthy lifestyle, intracranial or intraocular pressure. Often the pathology is diagnosed in premature babies or babies born with low weight.
The risk of developing the disease increases with age; after 40 years, many people complain of deteriorating near vision.
Forms of refractive error
The following forms of refractive error occur in medicine:
- Myopia (myopia). As a result of the elongation of the eyeball and excessive refractive power, rays of light passing through optical system eyes meet in front of the retina. This results in a person seeing images up close clearly, but objects far away appear blurry. The patient complains of blurry pictures, headaches, and constantly squints his eyes when trying to look at something in the distance. To improve vision, correction with diverging lenses is necessary.
- Farsightedness (hypermetropia). The focal point of light rays is located outside the retina, since the eyeball is too short and the refractive power is insufficient. With farsightedness, a person sees clearly what is in the distance, but the image up close becomes blurry. With age, problems often arise with visibility over long distances. The pathology is manifested by difficulties with reading, using the telephone or other objects nearby, discomfort in the eyes, which is why the patient constantly rubs his eyes and blinks frequently. Migraines often occur. Converging lenses are prescribed for treatment.
- Astigmatism. The cornea or lens of the eye has an irregular shape, as a result of which accommodation is impaired, a person sees a blurry image at any distance. With this anomaly, blurred vision, diplopia, eye fatigue, burning sensation, pain, and migraine are observed. Corrected with cylindrical glasses or toric lenses.
Sometimes there are such varieties of ametropia as presbyopia (), resulting from sclerotic age-related changes in the lens.
Features of the development of myopia
What refractive error leads to the development of myopia? Myopia is a visual defect in which a person sees distant objects blurred. The normal eyeball is about 23 mm. With myopia, its size increases and reaches 3 cm. This leads to the fact that the focus of refractive light rays shifts, folding not on the retina itself, but in front of it. As a result of a violation of accommodation, the brain receives a blurry picture, clarity visible to humans items is significantly reduced.
Myopia is a common phenomenon that can be congenital or acquired. Most often, the pathology is diagnosed in people aged 40 years. On initial stage diseases when the refractive error is minimal and amounts to less than 3 diopters, the person practically does not notice changes, there is no need for correction. But in the absence of therapy, the pathology progresses, first going into middle stage(3-6 diopters), and then to high (over 6 diopters). In advanced cases, complex treatment is necessary.
Diagnostics
To make the correct diagnosis, as well as determine the cause and treatment method for refractive error, the ophthalmologist listens to the patient’s complaints, collects a detailed medical history, and then carries out the following diagnostic measures:
- Ophthalmoscopy– the fundus of the eye is examined. In the presence of myopia, degenerative-dystrophic changes in the macula are detected.
- Visometry– the degree of visual acuity is determined using special tables. The Sivtsev-Golovin tables are most often used.
- Computer refractometry. Clinical refraction is examined using a special device.
- Perimetry– the thickness of the cornea is studied. Allows you to detect astigmatism (in this case, some areas of the visual field fall out).
- Biomicroscopy– assessment of the state of accommodation and visual apparatus using a special apparatus.
- Ultrasound of the eyes– measurement of parameters of the organs of vision. Allows you to study in detail the condition of the eye structures and diagnose the problem.
Depending on the results obtained, the doctor may prescribe additional instrumental or laboratory research, consultations with other specialists.
Treatment methods
In case of refractive error, they may be prescribed following methods corrections:
- spectacle correction;
- lens correction;
- laser correction.
Treatment tactics are selected individually and depend on the form of ametropia. Treatment for refractive error may look like this:
- Myopia. Dispersive (minus) lenses are prescribed to normalize the focusing of light on the retina. At the initial stage of myopia, you need to wear glasses only as needed, when you need to see something in the distance. With a more advanced degree of pathology, wearing glasses should be permanent.
- Farsightedness. Converging (plus) lenses are prescribed to facilitate proper focusing of light. Lenses may be recommended when there is an individual intolerance to glasses or anisometropia is diagnosed.
- Presbyopia. It is necessary to wear spherical converging lenses.
- Astigmatism. Special cylindrical glasses or toric contact lenses are selected.
If spectacle or lens correction does not bring positive result or the degree of refractive error is too high, it is recommended to laser correction. This method is safe and effective, the cornea is not injured, rehabilitation period absent. The correction is carried out by changing the thickness of the cornea using a special excimer laser.
In the most advanced cases, surgical intervention is performed, in which an artificial lens is installed or phakic lenses are implanted. Sometimes a keratotomy is done or.
