Infectious and inflammatory eye diseases are a fairly common pathology among ophthalmic diseases. The reason for the development of the infectious process can be noncompliance with personal hygiene rules, traumatic eye damage, contact with a person who has a similar pathology. In some cases development of an infectious and inflammatory process is observed against the background of a decrease in the general body resistance to the action of viral and bacterial agents. Most often infection affects eye against the background of diabetes mellitus, long-term use of hormonal drugs, and alcohol abuse. Symptoms of diseases are diverse and depend on the type of pathogen and what particular structural part of the eye is affected. Viruses (adenoviruses, herpes simplex virus), bacteria (Staphylococcus aureus, gonococcus), chlamydia and even fungi can act as infecting agent. Conjunctivitis, keratitis, blepharitis, uveitis, dacryocystitis, etc. are distinguished depending on what part of the eye is affected. Diagnosis of infectious and inflammatory processes affecting the organs of vision is carried out by visual inspection, using a slit lamp, if necessary, as well as taking sample for the microbiological test in order to determine the type of pathogen. Ultrasound or computed tomography is indicated in some cases.

Orthokeratology is a method of non-surgical correction of refraction, which is based on the principle of biomechanical changes in the curvature of the cornea under the influence of «reverse geometry». This method was developed more than 50 years ago, however, it became widely used only in the early 2000s. The basis of this method is the use of special orthokeratology lenses that patients wear during the night. Peculiarity of these lenses is the ability to change curvature of the cornea, resulting in a flattening of its central part and thickening of the paracentral and peripheral sections, which leads to the formation of positive spherical aberration of the optical system. Such changes in the cornea resulting from partial desquamation of keratocytes and changes in their shape during 7–8 hours of influence during the night, lead to the normalization of refraction, which persists for the next 24 hours. Most often this method of vision correction is used in children and adolescents, since it allows not only to optimize visual acuity for a certain period of time, but also to stop the progression of myopia. Another indication for the correction of vision using orthokeratology lenses includes active sports and situations that exclude the possibility of wearing glasses or soft contact lenses.

Glaucoma is a disease with multiple etiologies, which is based on increased intraocular pressure, leading to impaired visual fields and pathology of the optic nerve. Increase in the hydrodynamic load on the optic nerve disk occurs as a result of increased pressure, this is gradually leads to its atrophy. Progressive narrowing of the visual fields is another classic sign of glaucoma. This disease is one of the main causes of vision loss and related disability in the population. There are three main forms of glaucoma – primary open-angle, primary angle-closure, and secondary glaucoma, which develops against the background of existing eye pathology (diabetic retinopathy, acute iridocyclitis, post-thrombotic ophthalmopathy). Primary open-angle glaucoma is the most common form of the disease, which usually affects older people. The angle-closure form of glaucoma is less common, but it poses a great danger. Often this form of the disease is observed against the background of existing hypermetropia. This type of primary glaucoma develops as a result of impaired outflow in the drainage system of the eye due to the collapse of Schlemm's canal. Anterior chamber is significantly reduced in size or even disappears, and the lens is closely adjacent to the cornea. Angle-closure glaucoma has a paroxysmal form, rapid progression, and a less favorable prognosis. An acute attack of angle-closure glaucoma in some cases requires immediate hospitalization with subsequent surgical intervention.

Refraction of the eye means its ability to bend (refract) light in its own optical system. In a normal state, which is called emmetropia, light rays passing through the optical system of the eye focus on the retina, from where the impulse is transmitted to the visual cortex of the brain and is analyzed there. A person sees equally well both in the distance and near in this situation. However, very often, refractive errors develop as a result of various types of influences. Myopia, or short-sightedness, occurs when the light rays are focused in front of the retina as a result of passing through the optical system of the eye. In this case, a person will clearly distinguish close objects and have difficulties in seeing distant objects. On the opposite side is development of farsightedness (hypermetropia), in which the focusing of light rays occurs behind the retina — such a person sees distant objects clearly, but outlines of closer objects are out of focus. Near vision impairment in old age is a natural process called presbyopia, it develops due to the lens thickening. Both myopia and hypermetropia can have different degrees of severity. The variant, when different refractive errors are observed in different eyes, is called anisometropia. In the same case, if different types of refraction are observed in the same eye, it is astigmatism, and most often it is a congenital pathology. Almost all of the above mentioned refractive errors require correction with spectacles or use of contact lenses. Recently, people are increasingly resorting to the methods of surgical vision correction.

Keratoconus is a dystrophic disease of the cornea, when it is thinned with the formation of a conus-like protrusion (protrusion of the cornea). This disease belongs to the group of keratectasia, it has a multifactorial nature and occurs in approximately 25 % of all corneal pathologies. The disease can be either primary, which is based on dystrophic changes in the cornea, or secondary, which develops against the background of prenatal keratitis. Keratoconus of iatrogenic origin, which develops as a result of refractive eye microsurgery, has become widespread during the last 20 years. Most often primary keratoconus manifests during puberty, progresses to 30–40 years, after which its development slows down. An early clinical manifestation of this corneal pathology is a progressive decrease in visual acuity, development of double vision (binocular diplopia) with the development of a strong headache against this background. Monocular polyopia — images and symbols with multiple contours — develops subsequently. Severe dry eyes, itching, photophobia appear in advanced stages. Diagnosis of keratoconus in some cases can be a significant difficulty, since the use of conventional research methods only allow to suspect refractive errors in the form of myopia or astigmatism. It is necessary to take into account the impossibility of correcting visual impairment using conventional methods — glasses or contact lenses — to make correct diagnosis. As a rule, diagnosis of keratoconus requires use of expanded spectrum of instrumental research methods.

The term “athlete's heart” was first described in 1899 by S. Henschen. This concept refers to the activation of physiological adaptation mechanisms and structural remodeling of the heart in sports medicine. The article presents the basic concepts used in sports medicine, signs of an "athlete's heart", physiological manifestations and pathological abnormalities that require attention from a doctor are highlighted. The most common causes of cardiovascular complications in professional sports are indicated. Today, the fact that physical activity of low intensity favorably affects the state of the cardiovascular system causes no doubt, while overloads or their absence of any loads are of no use.

Cataract is partial or complete lens opacity, and is one of the main causes of low vision and reversible blindness in the world, affecting every sixth person over the age of 40 years and the vast majority of the population by 80 years. Taking into account gradually increasing life expectancy, which is especially characteristic of economically developed countries, an increase in the number of cataract patients from the present 20 million to 40 million people is predicted by 2021.

Glasses, if to sort things out, are one of the most remarkable inventions of mankind, which has given millions of people the opportunity to perceive the world through vision. Prototype of the first glasses — they were the thinnest emerald plates enclosed in a bronze frame — was found in the tomb of Tutankhamun according to historical information. Ancient Greeks and Romans did not know the glasses unlike the ancient Egyptians and used pieces of rock crystal for reading, they preferred to use monocle prototypes, i.e., devices for one eye. Medieval monks also tried to use pieces of rock crystal or quartzite as lenses, which after some time they began to place in a frame. Arabs were the first to come up with a glass ball as an optical device. It is believed that glasses for the protection against the sun and sun glare were invented even earlier than glasses for vision correction. It is noteworthy that this invention belongs not to the southern, but to the northern peoples –inhabitants of Greenland were the first to come up with the use of bone plates with narrow slots that protected eyes from the snow shining in the bright sun.

Brazil is the largest country in South America both in terms of population and area, while the country ranks fifth in the world in terms of territory. About 200 million people live in the country, the average life expectancy as of 2019 was 75.7 years, Portuguese is official language. Healthcare in Brazil at the present stage occupies a rightful place in the ranking of world health care systems. Not much is allocated for healthcare needs according to the European standards — about 8.5 % of GDP. However 1 % from any banking transaction in the country goes for medicine. At the same time the state pays close attention to health issues, fully providing financing for such costly areas as the treatment of HIV-associated pathology and hepatitis C, hemodialysis, and insulin therapy. But it was not always this way. Until 1988, before the right of all citizens to receive guaranteed medical care was enshrined in the Brazilian Constitution, healthcare in the country was available only to wealthy segments of the population, while the poor could only rely on the provision of medical services as part of charity. National Health System was established in the country in 1990 due to the adoption of the Constitution, which proclaimed the right to health as one of the fundamental human rights. Today, this system is one of the largest public health systems in the world, which covers provision of health care for about 200 million people. The country moved from the category of «recipient» of medical care at the world level to the category of «donor» not so long ago, and is very successful in this. This is one of the few states where public health interests of the nation are put above economic ones. This fact was confirmed during the tobacco control company. Brazil, being a major exporter of tobacco products, took an active part in this company, despite the fact that it suffered major economic losses [1].

Decision to celebrate World Allergy Day was adopted in 2005 at the initiative of the World Allergy Organization. The purpose of the initiative is to inform the general public about the symptoms of allergic manifestations, to promote regular inspections and examinations. One third of the adult population of the Russian Federation and one fourth of children and adolescents periodically suffer from manifestations caused by allergies. This disease is an immunopathological response of the body to the action of an agent as a result of the development of sensitization to it. Currently, there is a tendency to a steady increase in the manifestations of allergic responses, scientists attribute this to the increasing use of various preservatives, chemicals, dyes, new drugs, and cosmetics in everyday life. The main symptoms and manifestations of allergies include runny nose, red eyes, lacrimation, wheezing, bronchospasm, shortness of breath, various skin rashes, and headache can sometimes appear. One of the most dangerous manifestations of allergy is anaphylactic shock, which manifests itself in the form of itching, severe respiratory failure, profuse sweating, thready pulse, and a drop in blood pressure. This condition can be fatal if medical assistance is not provided on time.

Worldwide, December 3 is the international day of persons with disabilities. As early as 1982, a 10-year programme of action for persons with disabilities was adopted, called the Decade of persons with disabilities, and at its end in 1992, the General Assembly declared December 3 as the International day of people with disabilities. The goal of this day was to promote the rights of persons with disabilities in all spheres of public life, as well as to attract the attention of the General public to the problems of disabled people. Every year there are more and more people with disabilities, so only in the Russian Federation the total number of disabled people is 9% of the population. Someone comes to terms with their fate and closes in the walls of their home, and someone continues to lead an active life, not wanting to change something in the usual way in connection with their new status. Such strong-minded people learn new professions, acquire previously unknown skills, and try to expand their horizons in various ways available to them. And some unique individuals in the desire to prove to others, and first of all to themselves, that disability is not a sentence, even take part in sports competitions organized specifically for people with disabilities. And if for any famous athlete participation in the Olympics, and even more so victory in it, is a matter of prestige and world recognition, for a disabled person participation in the Paralympic games primarily means victory of the spirit over the body, victory over their own helplessness and infirmity, recognition of the fact of beauty and fullness of life.