Myopia

What is myopia?

According to medical statistics, about every fourth human on our planet suffers from myopia of varying degrees.

In myopia, a person can have difficulty clearly seeing objects at some distance. Due to this, it is problematic to perform not only professional duties, but also simple household chores.

This visual impairment is due to the fact that the light rays entering the eye are focused not on the retina, as it should be, but in front of it. As a result, people see a blurred image of those objects that are no further than a couple of meters from them. Why does this happen?

Myopia can be usually explained by the structural features of the visual organ or strong light refraction. It is no coincidence that this anomaly is called myopia. This word comes from the ancient Greek and literally means ‘to squint’: a short-sighted person squints, trying to see something.

If myopia is not corrected, additional visual disturbances may appear, namely: presbyopia, astigmatism, strabismus, etc.

To correct myopia, special optical eye care is used – glasses, lenses. Good results can be achieved with modern laser techniques and other types of surgical operations.  

Myopia degrees

Experts distinguish three basic degrees of myopia, namely:

• Weak – up to 3 dioptres. With such disorder, a person sees well up close, but images become blurred, when looking into the distance.
• Medium – from 3.25 to 6 dioptres. With such a diagnosis, a person usually sees well at a distance of up to 30 cm, and everything which is far begins blurring.
• High – over 6.25 dioptres. With such indicators, good vision is maintained at a distance of up to 5-10 cm.

A dioptre (D) is a unit of measurement for refraction – the power of optical systems. In case of myopia, negative power lenses are prescribed, for example, -2. Optics are selected based on the results of examination in an ophthalmology clinic.    

What causes myopia and its development

Myopia can be congenital and acquired. In the first case, the causes of the disorder are the peculiarities and malformations of the visual organ, in the second one – unfavourable external factors. Let us consider some of them. 

• Hereditary background. If one of the parents is diagnosed with myopia, the probability of developing this visual disorder in a child is 25%. There is a risk that the child will inherit the same physiological defects as the parents (for example, the wrong size of the eyeball).
• The shape of the eyeball. Poor visibility of objects at a distance is due to a discrepancy between the optical power of the eye and the length of the eyeball. Normally, the anteroposterior axis of the eye in an adult is 24 mm long. With myopia, its lengthening is observed. For example, weak myopia is characterized by an increase in the length of the eye axis by 1.5 mm, and with high myopia, it can be 30 mm. 
• Scleral weakening. Myopia can be triggered by weakness of the eye muscles and scleral tissues, which, in turn, can be a hereditary defect (for example, with a genetic disorder of protein synthesis of connective tissues). 
• Working conditions. Nowadays, when many types of professional activities are fraught with increased visual load, this factor is determining in the development of myopia. Not only adults suffer, but also children who, from an early age, expose their eyes to increased stress – many hours of watching TV, playing on a computer and smartphone, reading lead to eye strain. Working in poor lighting is another common cause of visual disorder.  
• Improper nutrition. Lack of vitamins and minerals has a significant effect on eyesight. Deficiency of vitamins of group A, B, C, E, zinc, magnesium, iron, phosphorus, calcium increases the risk of developing myopia. 

Prevention of myopia

If myopia is triggered by such anatomical abnormalities as an irregular shape of the eyeball or a violation of protein synthesis, it is impossible to prevent developing such disorder. But it is quite possible to slow down further deterioration of eyesight and avoid progression of myopia, especially since modern ophthalmological clinics offer a fairly wide range of techniques. Ocular Institute of Ophthalmology recommends:

• To keep to a diverse diet. Try to consume as many vegetables, fruits and other foods rich in vitamins and essential micronutrients as possible.
• To provide proper lighting for the workplace.
• To avoid eye strain. Take breaks while reading, working on the computer, watching TV. Don’t forget about eye exercises.
• To try to spend more time outdoors.
• To undergo a routine examination by an ophthalmologist once a year.
• For any suspicious symptoms (decreased visual acuity, eye pain, excessive tearing, dry eye, seeing spots, seeing double, etc.), you should immediately contact a specialist.
• Observe all doctor’s recommendations after revealing myopia.