Myopia

Nearsighted people very much, some of them see well and do not pay attention to his defect, other short-sightedness is becoming a problem: blurred vision interfere live and work or do not allow you to choose one or another profession. In most cases, all of these people can be helped with corrective eye glasses, lenses or by surgery. As is known, the eye is an optical system, which refracts rays of light reflected from a particular subject.

In the optical system of the eye include: the outer casing of the front surface of the eye (the cornea), as well as the crystalline lens, vitreous body and aqueous humor, which fills the cavity of the eyeball. This refraction of light is called refraction. In normal refaction refracting rays intersect at the rear of the inner membrane of the eye. At various violations of refraction they intersect, or before or after the inner membrane of the eye.

Myopia and its causes

Myopia - Myopia is, that is such a visual impairment, where people could see up close and bad - into the distance. Greek myopia is translated as "squint eye." This name arose because for a short-sighted man squinting characteristic, it can more clearly see distant objects.

If myopia is a violation of refractive power - the rays of light entering the eye after refraction does not overlap on the retina, and in front of her because of violation of the contractile capacity of the ciliary muscle. The reasons for this phenomenon can be two: increase the size of the eyeball in the anteroposterior direction (axial myopia), and strengthening eye refractive power (refractive myopia).

Most of myopia appears during prolonged stress view. In the initial stages it may be just a spasm of the muscles governing the curvature of the lens (ciliary muscle) and it can be removed with the help of antispasmodic (relieves spasms) drugs. If at this moment not to take the necessary measures, it violated the contractile ability of the ciliary muscle and myopia becomes permanent.

The symptoms of myopia

Myopia may be different degrees, from mild, in violation of refraction up to 3.0 diopters, to moderate (3.0 - 6.0 diopters) and a high of 6.0 and above, in some cases up to 30.0 diopters.

The weak and the average degree of myopia usually does not interfere with a person engaged in professional work and lead a normal life. Frequent squinting leads to the appearance of fine wrinkles at the corners of the eyes of such people sometimes, especially after an intense visual load, they start to flicker "fly" before their eyes, are not particularly alarming, and can pass on their own.

The high degree of myopia may be a problem for humans. Correct it is not as easy as a weak and secondary degree. Since the eyeballs of the people is rapidly increasing in the anteroposterior direction, their appearance has the characteristic features: the eyes are made prominent, eye-slit widened eyes wide.

There is a special form of myopia - a progressive or malignant. The peculiarity of this form is that the eyeball is growing very rapidly, increasing the degree of myopia. This is fraught with complications, as well as stretching the inner membrane of the eye (retina), and disrupted the activities of the blood vessels. Such growth of the eyeball can cause hemorrhage and retinal detachment, which will lead to severe disturbances of vision.

Diagnosis of myopia

The diagnosis of myopia is usually put on the basis of complaints, placed on the patient and the examination ophthalmologist confirmed the data of instrumental investigations.

First of all, with the help of special tables tested visual acuity with special lenses that eliminate nearsightedness. Then, a skiascopy - a special study that conclusively proves the presence of myopia. But the doctor directs a beam of light in the pupil of the patient, rotating the ophthalmoscopic mirror. Moving the light spot in the illuminated pupil with normal vision, farsightedness and nearsightedness is less than 1 diopter in one direction, while above 1.0 diopters of myopia - in another.

To confirm the short-sightedness and determination of its extent, is also being refractometry eyes - the measurement of refraction with the help of special devices (refractometer). With the help of ultrasound measured length of the eyeball in the anteroposterior direction and the thickness of the cornea.

Ends with a survey exception of complications. This is held ophthalmoscope - fundus examination of the state (visible inner surface of the eyeball) with a special instrument - ophthalmoscope.

Treating myopia

Myopia can be treated by correcting glasses, contact lenses and with the help of surgery. The latter type of treatment is becoming increasingly popular. In myopia weak and moderate laser cut a very thin layer of the cornea, thereby reducing its refrangibility, resulting in myopia completely passes. At high degrees of myopia such an operation does not work, so such patients to remove the lens, replacing it with individually matched with a soft lens.

Durables careful treatment (both conservative and surgical) requires progressive malignant myopia, as well as treatment of complications of myopia.

Prevention of myopia

For the prevention of myopia to exclude unnecessary approximation of objects to the eyes, the strong inclination of the head forward and down. Operating room should have good natural and artificial lighting.

Persons with complicated myopia should avoid anything that might cause a rush of blood to the head, use tinted glasses, moderate-intensity, to avoid physical and mental stress.