Myopia (myopia) is a visual impairment, in which it is difficult to see into the distance and well – at close range.
It is customary to distinguish three degrees of myopia: weak – up to 3.0 diopters, medium – 6.0 diopters, high – over 6.0 diopters.
Downstream distinguish myopia non-progressive and progressive. The progression of myopia can proceed slowly and end with the completion of the growth of the organism. Sometimes myopia progresses continuously, reaches high degrees (up to 30.0-40.0 diopters), is accompanied by a number of complications and a significant decrease in vision. Such a myopia is called a malignant – myopic disease.
Non-progressive myopia is manifested by decreased vision at a distance, it is well corrected and does not require treatment. Favorably and temporarily progressive myopia. Constantly progressing myopia is always a serious disease, which is the main cause of disability . associated with the pathology of the organ of vision.
Manifestations of myopia are associated with the presence of primary accommodation weakness, over-tension of convergence and stretching of the posterior part of the eye, occurring after the eye stops growing.
Stretching the posterior segment of the eyeball leads to anatomical and physiological changes. Especially sharply on the visual function affect violations in the choroid and retina. The consequence of these disorders are typical for myopia changes in the fundus.
Stretching of the eye membranes is accompanied by increased fragility of blood vessels with repeated hemorrhages in the retina and vitreous body. Slowly absorbable hemorrhage leads to clouding of the vitreous body. Of particular importance is the formation of a rough pigmented lesion, which greatly reduces visual acuity. Visual impairment may also occur due to the progressive clouding of the vitreous body, its detachment and development cataracts . A very serious complication of high myopia is retinal detachment, which develops due to its rupture in different parts of the fundus.
In the development of myopia should be considered the following factors.
- Genetic, undoubtedly of great importance, as myopic parents often have myopic children. This is especially evident in large groups of the population. So, in Europe the number of myopes among students reaches 15%, and in Japan – 85%.
- Adverse environmental conditions, especially during long-term work at close range. This is a professional and school myopia, especially easily formed when the development of the organism is not completed.
- Primary accommodation weakness, leading to compensatory stretching of the eyeball.
- Unbalanced tension of accommodation and convergence, causing a spasm of accommodation and the development of false, and then true myopia.
Correction of myopia carry out scattering glasses. When assigning glasses, they take as a basis the degree of myopia, which is characterized by the weakest scattering glass, which gives the best visual acuity. In order to avoid the appointment of negative glasses with false myopia, visual acuity in childhood and adolescence is determined in the state of relaxation of the ciliary muscle (atropine is instilled into the eyes).
In cases of mild myopia, a full correction is usually recommended, equal to the degree of myopia. Wearing these glasses can not always, but only if necessary. In case of myopia of medium and especially high degree, complete correction when working at close range causes an overload of ciliary muscle weakened inmyopes , which is manifested by visual discomfort when reading. In such cases, especially in children, two pairs of glasses are prescribed (for distance – complete correction of myopia, for working at close range with lenses by 1.0–3.0 diopters weaker) or for permanent wear bifocal glasses, in which the upper part of the glass serves for vision distance, and the bottom – near.
Recommended special exercises for training ciliary muscle.
In case of highly complicated myopia, in addition, a general, sparing mode is shown: exclude physical stresses (weight lifting, jumping, etc.) and visual overload. Complications such as retinal detachment and complicated cataracts require surgical treatment.
Surgical treatment of myopia is now widespread. Research in this area is carried out in two main directions: strengthening the stretching posterior segment of the eyeball and reducing the refractive power of the eye.
In the last 20 years, operations on the cornea have been developed, performed to change its refractive ability. Operations on the cornea for myopia, of course, do not prevent its progression and the occurrence of complications.
With regard to high myopia, then with her main task – to prevent its progression and the development of complications. Scleroplastic operations play an important role in this . Their meaning is to impose a kind of bandage, mainly on the back of the eye, to prevent further stretching of the sclera in this section. The effect of scleroplasty in myopia is to stop or sharply slow the progression of myopia, as well as to slightly decrease the degree of myopia and increase visual acuity.
Physical culture with myopia
Restriction of physical activity of persons suffering from myopia, as recommended recently, is considered incorrect. The important role of physical culture in the prevention of myopia and its progression is shown, since physical exercise contributes both to the general strengthening of the body and enhancing its functions, and to improving the efficiency of the ciliary muscle and strengthening the scleral shell of the eye.
Cyclic physical exercises (running, swimming, skiing) of moderate intensity (pulse 100–140 bpm ) have a beneficial effect on the blood circulation and accommodative ability of the eye, causing a reactive increase in blood flow in the eye some time after exercise and increasing the efficiency of the ciliary muscle. Afterperforming cyclic exercises of considerable intensity (pulse 180 beats / min), as well as exercises on gymnastic equipment, jumping with a skipping rope, and acrobatic exercises, a deterioration in the performance of the ciliary muscle is observed.
The main contraindications to sports for people with myopia
Children with mild myopia are included in the main group and can engage in physical education in the preparatory department of sports improvement. Useful sports games. Constant switching of vision when playing volleyball, basketball, tennis from close to far and back helps to enhance accommodation and prevent the progression of myopia.
In the presence of moderate myopia, children are included in the preparatory medical group; they should be engaged in physical culture in the preparatory educational department. Practical exercises with them should be carried out separately from the main medical group.
It is advisable to introduce some restrictions into the program requirements for them: to exclude jumps from a height of more than 1.5 meters, exercises that require a lot of physical exertion. The degree of neuromuscular tension and the total load during physical training should be somewhat lower than that of students from the main medical group. For students of the preparatory medical group, along with training sessions, it is also necessary to provide for independent studies, including special exercises for the muscles of the eyes or physical therapy exercises.
Students with a myopic high degree (6.0 diopters and more) should be engaged in physical culture only in a special medical department.