Myopia (nearsightedness)

What is myopia? Myopia, also known as nearsightedness or shortsightedness, is an eye disease that occurs  if the eyeball is too long or the cornea has too much curvature. This is a visual impairment that prevents you from seeing objects in the distance. A short-sighted person can hardly distinguish distant objects: people's faces, road signs, inscriptions on billboards. At the same time, he can see close objects clearly.

There are the following types of myopia (nearsightedness):

1. By degree:

• low (up to –3.0 diopters);
• moderate (–3.25 - –6.0 diopters);
• high (more than -6 diopters).

2. By the time of appearance:

• congenital;
• acquired.

In a healthy eye, light rays are uniformly refracted by optical media (the lens and cornea) and fall directly onto the retina. This is possible due to the correct relationship between the refractive power and the length of the anteroposterior axis of the eyeball. In the myopic eye, this ratio is broken. Optical media refract light much more than it is necessary for normal visual perception. As a result, light rays are focused in front of the retina. Because of this, the image of distant objects seems blurry to a person.

Factors contributing to the development of nearsightedness are the following:

• long hours on computer or phone;
• abuse of computer games;
• hormonal changes in adolescence;
• lack of certain vitamins and minerals;
• immune system disorders;
• violation of the structure of connective tissue, which forms the sclera and maintains the shape of the eyeball.

The main task of the doctor is to prevent the development of myopia and prevent progression if it occurs. Stretching the eye with progressive myopia leads to thinning of the sclera, especially in the posterior pole of the eye. It can cause degenerative changes in the macular area, peripheral dystrophy and retinal detachment.

To improve vision of the patient who suffered from myopia, the following methods can be used:

• eyeglasses for correction;

• corrective contact lenses;

• surgical methods of treatment.

Surgical method includes a laser refractive operation, the task of which is to change the refractive power of the cornea of the human eye with an excimer laser. Today, two methods of excimer laser refractive surgery are widely used in the world. The most popular option is LASIK. However, when LASIK surgery is not possible, for example, due to insufficient thickness of the cornea, photorefractive keratectomy (PRK) is recommended.