What is myopia: "plus" or "minus"?

Myopia (myopia) is a serious problem, which is associated not only with visual impairment, but also with an increased risk of complications.Short-sighted people are difficult to carry out many activities: drive a car, read signs, information scoreboard, and with a high degree of myopia it is not easy even to see a familiar face at a distance of one to two meters.

According to the World Health Organization, this problem affects up to 30% of the world's population. The number of patients suffering from this myopia is steadily growing. Very often the violation occurs in schoolchildren, students. People with good eyesight sometimes do not understand,What is myopia: "plus" or "minus"?Let's look at this problem together.

What it is?

Myopia is a visual impairment, in which a person can see things that are far away, but can see objects that are very close. Myopia is also called myopia.

One of the main components of the eye is the cornea and the lens. They are able to pass and refract the rays of light. An image appears on the retina of the eye, which is transmitted to the brain with the help of nerve impulses along the optic nerve.

If the cornea and the lens refract the rays so that the focus is on the retina, then the image will be clear, and the vision - one hundred percent.

With myopia, the image is blurred and fuzzy due to two abnormal factors:

1. The eye is very elongated, and the retina deviates from the stable location of the focus. With myopia in humans, the eye reaches 30 millimeters. And for a normal healthy person, the size of the eye is 23-24 mm.
2. Lens and cornea refract light rays too much.

People with myopia find it difficult to examine objects that are far away from them. But near-sighted objects, myopic person sees well.

Causes

Nearsightedness most often develops in school years. Heredity plays an important role in the development of pathology. It is important to consider, one or both parents suffer from this disease. If there is a violation in the father and mother, in 50% of cases it will occur in the child before entering into adulthood. If the parents are healthy, the risk of developing the disease is significantly reduced and is 8%.

Among the main factors contributing to the development of myopia, you can identify a long-term work at close range in poor hygienic conditions or poor lighting. This reason is especially relevant today due to the massive spread of computers.

Distortion of the lens and reflection of objects

The development of myopia is also facilitated by the weakening of the eye muscles.To solve this problem, special sets of physical exercises have been developed, which can be used both for curative and preventive purposes.Therapeutic exercises for the eyes slow the progression of myopia. Previously, ophthalmologists often recommended that myopic patients limit their physical activity. However, today the opinion of oculists has changed: moderate loads are recommended with a rational regime of rest and sleep.

At a young age myopia can be caused by:

• spasm of accommodation;
• keratoconus (change in the shape of the cornea);
• displacement of the lens with trauma (dislocation, subluxation);
• sclerosis of the lens.

The latter pathology leads to the development of myopia in old age.

There are other reasons that lead to the development of myopia:

• Lack of nutrients, vitamins, minerals in the body. To a greater extent, the vitamins of group B and C, as well as trace elements such as magnesium, zinc, copper, manganese, affect the vision.All of them are necessary for the proper development and formation of the sclera of the eye.
• Any overexertion of the eyes caused by prolonged and continuous visual work.
• The lack of competent correction in the appearance of the first symptoms of myopia.If the first signs of the disease are ignored, myopia will progress and lead to a significant deterioration in vision.
• Incorrectly selected glasses or contact lenses for correcting vision with the onset of myopia.
• Congenital pathology (for example, weakness of the eye muscles responsible for changing the curvature of the lens).
• Some eye diseases(strabismus, astigmatism, etc.).
• Increased intracranial and intraocular pressure.
• All conditions that cause weakening of the body and impair the supply of nutrients to the eye (some infectious diseases, failures in the hormonal system, birthmarks and craniocerebral injury).

Symptoms

The main symptoms of myopia are as follows:

• Fuzzy vision of distant objects;
• "Flies" before the eyes;
• frequent headaches;
• fast eye fatigue;
• bifurcation of objects;
• violation of twilight vision (in the dark, nearsighted people with difficulty operate the machine and are not oriented on the street);
• errors in the definition of color.

Depending on the degree of myopia, the patient's vision can range from slight fuzziness in the distance to full blurring of the image, even a few meters from himself.

Patients with a high degree of myopia can be seen literally at the very nose, but the further point of a clear vision lies just a few centimeters from the eye.

Short-sightedness can be combined with other visual ailments, for example, with astigmatism. Signs of such a complicated form of the disease are:

• bifurcation of objects;
• distortion of objects;
• Curved lines (instead of straight lines).

"Plus" or "minus"?

After the study of visual acuity, all patients with refractive failure are subjected to a trial correction of vision with the help of lenses.Lenses are of two types: scattering, denoted in the ophthalmology sign (minus), and collecting - denoted by the sign "+" (plus).

Focus of the diffusing lens

For correcting myopia, dissipative ("negative") lenses are used.In this way,when talking about glasses or lenses for correcting myopia, always mean "minus not "plus". But to correct farsightedness apply "positive" or collecting lenses, so farsightedness is a "plus". And what do figures mean, for example -2, 5 or any others?

The numbers denote the optical power of the lenses required for a patient with myopia to clearly see the 10th line in the Sivtsev table. The power of the lens is expressed in diopters and can have a fractional value. When you write out the prescription for glasses or for lenses for each eye, the value of the force of the lenses is indicated.

There is such a thing as "false myopia which is not related to eye changes and does not apply to either "minus" or "plus".This condition is caused by a constant overexertion of the eyes when working with closely located objects. False myopia is treated with exercises, sometimes with medications, but does not require wearing glasses or lenses.In order not to confuse true myopia with false vision and not to gain glasses in vain, it is necessary to immediately consult a doctor at the first signs of impaired vision.

The difference between the collecting and scattering lens

Diagnostics

Only the oculist can detect the disease, determine the degree of myopia and choose the most appropriate treatment for this case.

Diagnosis of myopia requires the conduct of such studies as:

• checking visual acuity without glasses;
• the definition of refraction (refraction) of the eyes and the degree of myopia;
• selection of correct lenses;
• the measurement of the length of the eye in the ultrasound;
• measurement of the thickness of the cornea at its various points;
• examination of the fundus (allows the doctor to assess the condition of the retina, vessels, optic nerve of each eye);
• selection of the method of correction and treatment.

The lack of correction of myopia or incorrectly selected glasses (lenses) can lead to rapid deterioration of vision and the development of progressive myopia.

Treatment

Treatment for myopia is a complex process, which can only be managed with the help of an ophthalmologist.

Modern methods of improving vision are diverse:

Eye correction with glasses

• Laser correction.
• Optical correction of myopia.
• Methods of surgical intervention.Used at a high degree of the disease. It is possible to replace the lens on the intraocular lens, installing the actual lens.
• Drug treatment of the disease.
• Correction of nutrition to improve the blood supply of the eye and the supply of nutrients to it.

Laser vision correction for nearsightedness

This is the most modern, safe and effective way to improve vision and get rid of the problem of myopia. Laser correction will allow the patient to refuse wearing glasses and contact lenses. The essence of the intervention is to change the shape of the cornea, thereby reducing its optical strength.With the help of a laser, it is possible to create the effect of wearing glasses, as if located inside the eyes, as a result of which the light rays after refraction in the lens focus on its retina.

Laser vision correction for nearsightedness

There are several methods of laser correction:

• LASIK (creation of corneal parameters by template);
• Super LASIK (creation of individual parameters of the cornea);
• KGF (used with a thin cornea and a low degree of myopia).

Each method has its own peculiarities and is applied depending on the state of the eyes and financial capabilities of a person.

Ophthalmic correction

Glasses are traditionally used to correct the vision of a patient suffering from nearsightedness.They are equipped with scattering lenses, which weaken the optical system of the eye and push the image back onto the retina. If myopia is complicated by astigmatism, you will need to wear glasses with the cylinders.

Contact correction

Today, contact correction is gaining popularity among young people. Contact lenses have a number of advantages over glasses. With proper selection and use, they provide a clearer vision than glasses.Good lenses allow you to fully restore visual acuity without distortion and aberration, which the best glasses can not provide.

Complications

In case of untimely treatment or illiterate correction of myopia, its progression is possible. There may be complications such as:

• formation of staphylitis sclera(protrusion);
• retinal dystrophy;
• hemorrhage on the retina and in the vitreous body;
• cataract;
• retinal disinsertion.

Cataract as a consequence of neglected myopia

Complications against myopia may occur at any age. In addition, the destructive processes on the retina sometimes develop after surgical treatment of myopia due to the altered shape of the eye, which is not corrected.

With myopia (especially high degree), it is necessary to regularly undergo examinations with an ophthalmologist that will help monitor the condition of the retina and will provide an opportunity to detect in time tears, holes, thinning.

Prevention

Any disease is easier to prevent than treat. Prophylaxis of myopia implies the following measures:

• Regulation of the lighting mode.Visual loads are allowed only in good lighting with the use of a ceiling light, a table lamp of 60-100 W. Do not work with fluorescent lights.
• Observance of the regime of visual and physical activity.It is recommended to alternate visual voltages with active, mobile rest: with myopia up to 3 diopters, the physical loads are not limited, over 3 diopters - heavy lifting, jumping and some kinds of competitions are forbidden.
• Gymnastics for the eyes(every 20-30 minutes).
• Correct vision correction, appointed by an ophthalmologist.
• Muscle training, the tension of which leads to the growth of myopia (laser stimulation, video-computer vision correction, eye drops, special courses of eye gymnastics).
• Ophthalmologic diagnostics: ultrasound measurement of the longitudinal size of the eye (1 time in six months).
• Common restorative measures(swimming, massage of the collar zone, contrast shower) on the recommendation of an ophthalmologist.
• Full balanced nutrition.

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The first signs of glaucoma of the eye.

Hyperopia is a plus or minus: http://eyesdocs.ru/zabolevaniya/gipermetropiya/opredelenie-dalnozorkosti-xarakternye-simptomy.html

The term of wearing contact lenses: everything about the types and rules of use is written in this article.

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conclusions

So, myopia (hypermetropia) is a disease that needs to be treated in time to prevent progression and many complications. With short-sightedness wear negative lenses, appointed by a doctor. Violation of the refraction of vision can lead to a complete loss of vision, so it is extremely important to prevent it and correct correction of myopia.