What is the cause of myopia development in humans

Ancient Greek philosopher Aristotle, who lived in the IV. BC. E., noticed that some people can not see far-away objects. In trying to look at them, they screwed up their eyes, so Aristotle called such a visual defect of "miops" (squint). Nowadays the disease is called "myopia but in medicine the term "myopia" is used, the interpretation of the name given to the ancient Greek scientist.

Definition of disease

The optical system of the eye is arranged so that the light rays, falling on the cornea and the lens, are refracted and pass through the vitreous body before reaching the retina, in particular the yellow spot (macula). Here is the largest accumulation of nerve endings that form the image before it enters the visual analyzer - the area of ​​the brain responsible for this function.

If any of the optical structures (cornea, lens, vitreous) changes its physical properties, the refractive force changes, and the image focus does not reach the retina (with myopia) or is outside the eyeball (when farsightedness).

Myopia can affect a person at any age, but most often it begins to manifest in children from 7 to 15 years, when the final stage of the formation of the visual apparatus takes place, and the visual load begins to gradually increase. It is then that the eyesight of children begins to fall. At the end of this period myopia either remains at a certain level, or continues to progress.

Causes

The violation of refraction (refraction of the light beam) in myopia occurs in most cases for the following reasons:

• Elongated shape of the eyeball;
• Too much refraction of the eye's optical system(in particular, the lens and the cornea).

In some cases, there is a combined disorder, when a person has both of the above-mentioned causes.

Such visual defects can arise under the influence of a number of factors, the most common of which are:

• Heredity.If there is such a defect in parents, the probability of developing myopia in a child is 50%; if the parents are healthy, the risk is reduced to 8%;
• Lack of food. For the functioning of the eye structures, like all tissues of other organs and systems, certain nutrients are needed. Disturbance of visual perception occurs with a lack of vitamins of group B and vitamin C, and also trace elements of magnesium, copper, zinc, manganese;
• Lack of vision hygiene. This group includes incorrect lighting, prolonged eye strain, non-observance of the minimum distance to books, computers, televisions, telephones;
• Eye pathologies: strabismus, astigmatism, etc. Such defects cause overstrain of the eye structures, promoting the development of myopia;
• High blood pressure. At high indices of arterial and intracranial pressure, slow destruction of blood vessels occurs, causing a deficiency of nourishment of the eye tissues.

Other possible causes of myopia development include any factors that cause a decrease in the overall level of immunity: infectious diseases, traumas of any kind, hormonal failures. The development of a visual defect is facilitated by incorrect correction in the form of glasses or lenses, as well as untimely it.

Symptoms

If you notice that your child starts squinting when examining distant objects, or if such a desire arises from you, it means that vision is undergoing changes in the direction of myopia, and urgent help is required ophthalmologist.

Other signs of manifestation of a defect may be:

• Blur the contours of distant objects;
• The world around me literally merges;
• Near vision remains clear and clear.

Of course, such strong symptoms do not appear immediately, but it is easier to prevent their progression at the early stages:

• 1 degree(up to -3 D) - the easiest, not causing any special problems. In this case, the eyeball increases only by, mm, and the disturbances are expressed only by the light blurriness of far-away objects;
• 2 degree(-3 -6 D) - the average degree of lesions, in which the eyeball is increased by 3 mm. This causes some discomfort, since already at a distance exceeding 30 cm, the sharpness of the image begins to decrease;
• 3 degree(over -6 D) is the highest degree of myopia, at which the eye undergoes significant changes, while the retina and vessels are in an extended state, subject to an increased risk of developing dystrophy. At this stage, the patient can see only the fingers at arm's length.

With progressive myopia, it is necessary to begin correction and treatment at the earliest stages, when it is possible to preserve the quality of vision in large volumes.

Possible complications

Progression of myopia, due to age-related changes and increased loads during this period, most often stops after reaching 20 years (in women) and 22 years (in men).By itself, the visual defect does not carry a danger, however, with the development of high degrees of nearsightedness, the threat of severe complications increases:

• Retinal disinsertion. Increasing the size of the eyeball entails its stretching and the threat of detachment and rupture, which can lead to loss of vision, partially or completely;
• Glaucoma.With dystrophic changes in the eye structures (most often age), it is possible to increase IOP, which in most cases leads to damage to the optic nerve and reduced visual acuity;
• Retinal dystrophy. It is the result of degenerative processes in the tissues of the eye, changes in the functioning of the circulatory system, and disruption of nerve fiber supply;
• Cataract. Violation of the patency of light rays through the lens is most often of an age nature, but in violation metabolic processes is not the last role played by overexertion of the eyes when trying to consider far-located objects.

The threat of complications can occur at any age, even after surgical correction. Therefore, even with a low degree of myopia, it is recommended that people take preventive examinations from an ophthalmologist.

Treatment

To determine the degree of myopia, the most traditional test is used - visometry.The patient at a distance of 5 m from the table with letters of different sizes calls them at the order of the doctor, and the doctor with the help of lenses with different values ​​of D determines the degree of myopia.

Carrying out the visometry

As additional methods for obtaining more complete results, the following methods are used:

• Ophthalmoscopy;
• Biomicroscopy;
• Investigation of refraction;
• Ultrasound examination.

Medication Therapy

Conservative methods are effective in treating myopia only in a complex and can include the use of:

• Medications.These are mainly means for relieving accommodation spasm and restorative medications;
• Vitamins:B, C, A, PP, as well as microelements: zinc, manganese, magnesium;
• Physiotherapy;
• Gymnastic complexesfor the eye muscles.

Complex treatment is recommended for all patients with varying degrees of myopia 1-2 times a year in order to prevent the progression of myopia.

Correction methods:

• Ophthalmic correctionis one of the most common methods in the treatment of a disease that has undoubted advantages: availability and ease of use. For young children, glasses are always prescribed, as the safest means;
• A variation of the method arecontact lenses, which can be worn by the older generation of children who understand the full responsibility for their application. Contact lenses have a great variety in quality and design of performance, but they are also not acceptable for everyone, since they can cause persistent feelings of discomfort. And this is fraught with the development of damage to the eye structures;
• Orthokeratology- the technique of using special lenses, when the patient wears them only at night. During sleep, lenses act on the corneal skin, flattening it, and in the daytime its shape is preserved, providing a quality of visual perception.

  Orthokeratological lenses

When the visual defect is eliminated in childhood, methods using special equipment can be used - the so-called hardware treatment.

Surgically

With progressive strong myopia, which can not be treated by other methods, the doctor can recommend one of the types of surgical intervention.For children, such operations are allowed only from the age of 18, since the formation of the visual system has not been completed before.

To correct myopia, the following types of surgery are performed:

• Laser correction- carried out using a laser beam, which corrects the degree of curvature of the corneal layer to the required value;
• Implantation of phakic lenses- Correction of curvature of the cornea in the space of the anterior (or posterior) chamber of the eye, a specially selected lens with the necessary properties is placed;
• Lensectomy(refractive lens replacement) - during the operation, the lens is replaced with an intraocular lens. This method is used most often for elderly patients, when the accommodation function is significantly reduced or lost altogether;
• Scleroplasty- used for progressive myopia (more than 1 D per year). Inside the eyes, a special plate is inserted, which prevents rupture of the retina with a rapid increase in the size of the eye.

  Laser correction

Folk remedies

The use of drugs according to folk prescriptions can be used as an additional therapy in the treatment of myopia:

• Take 2 tbsp. l. finely chopped herb flowers and fill them, l boiled water, after which it is insisted for 20 minutes. The filtered infusion is consumed 50 ml a little before meals three times a day;
• Spruce or pine needlesfinely ground, and 5 tbsp. l. 600 ml of boiling water are poured into the raw materials, after which they are baked in a water bath for 6 hours. In the received strained infusion add 1 st. l. honey and take 1 tbsp. l. three times a day after meals. The course of treatment - 3 months. ;
• At 10 o'clock l. warm boiled water is bred, h. l. honey.Bury 2 drops in each eye three times a day. Store the solution for no more than 2 days in the refrigerator, warm slightly before use;
• Infusion of plantain(2 hours) l. dry raw materials for 250 ml of water) is cooked on a low heat for 30 minutes. The filtered solution is taken 100 ml three times daily before meals.

The use of folk remedies can be effective with prolonged use, but before using them a doctor's consultation is mandatory, as they may have a negative effect if some diseases.

Prevention

In order to prevent a visual defect, it is first of all necessary to comply with the requirements of visual hygiene: Avoid overexertion when working at a computer, reading in transport or lying down, monitor the correct lighting.

Of no small importance in the general health of the eyes is a healthy diet, with the presence of natural vitamins, necessary for metabolic processes. And preventive examinations from an ophthalmologist can help to detect any abnormalities at the earliest stages.

Video

conclusions

Myopia is when you can hardly see in the distance. It is not a disease in the usual sense of the word, however, progressive myopia can cause severe damage to the eye structures and loss of vision, in whole or in part.

Therefore, the most attention should be paid to preventive measures and, in particular, regular medical examinations.