What is vision? Vision is the ability of a person to see objects of a larger and smaller size in the same conditions. It has been established in medicine that a person with vision can distinguish objects and parts located at a visual angle of 1 minute between them without any deviations. This vision is considered 100%. Very rarely there are people with 200% vision, even less so - with a value of 300%.
World record for visual acuity
In 1972, the University of Stuttgart set a record in its walls, which had never been recorded before. Student Veronica Sader surprised everyone with vision that exceeds the ideal vision of an average person by 20 times. She was able to make out and recognize a person by facial features at a distance of about 1600 meters.
Can visual acuity be affected?
The answer to this question was tried for many years in a row by scientists and doctors of ophthalmological sciences.
And in the end, they came to a common decision that through special training, you can increase visual acuity by 2-3 times. Of course, it is unlikely to succeed in breaking the record, but the visual apparatus will significantly improve its work. Much more effective exercises for "pitching" vision for children. Because they have visual muscles, like many others, more elastic than adults.
What should be the ideal vision in a person
The vision of an average person on the planet is 1.
This number indicates 100% vision. Normally, such a person can see two points in separate places located at an angle of 1 minute between them. To determine visual acuity in medical terminology, the numbers 0, 1, 1, 2 are used. In one eye of a person there are over 120 million cells that are sensitive to light. The cerebral cortex decrypts the information coming from the cells, produces it in various shapes and colors.
The retina of the human visual apparatus consists of rods and cones. The former are responsible for the ability to see gray in low light, and cones for colored objects and details. Ideal vision is easy to confirm, for this you need to visit the office of an ophthalmologist. The specialist will invite the person to consider special tables and symbols. It is very important that it is the tables hanging in the doctor’s office that can determine the visual acuity, but not the pictures from the Internet in the computer that “promise” to give an accurate result.
What tables are used to check visual acuity?
Today, there are several types of special tables, thanks to which it is easier for a doctor to determine how well or poorly a person sees.
- Golovin's table. This option consists of the same rings. They have holes in different parts of the “body”. The specialist indicates to the patient the rings that a person should consider, the patient should sit at a distance of 5 meters from the table.
- Snellen's table. It is used mainly in English-speaking countries. This table consists of 11 rows. The very first line contains one large letter. In each subsequent line, the size of the letters decreases, and their number in the row increases.
- Orlova table. It is used to test visual acuity in children. Here, instead of rings or letters, icons in the form of animals and plants are used. Vision is considered normal when a child sees the tenth line, sitting at a distance of 5 meters from the table.
- Sivtsev's table. This is the most common type of vision test. This table consists of the letters of the Russian alphabet, located in 12 lines. The letters in the top line are large, the lower the smaller they are. Ideal vision 0 is when a person manages to recognize letters from the tenth line from a 5-meter distance.
Visual apparatus abnormalities
The most common disorder associated with the operation of the visual apparatus is myopia. In medicine, it is called myopia. Such a disease is characterized by a person’s ability to see only objects, objects and details that are nearby. In the distance, he cannot consider them. Also characteristic of myopia is an increase in the eyeball. This pathology can be either acquired or obtained during childbirth, that is, congenital. The main symptoms of myopia are:
- weak distant vision;
- while the neighbor remains normal;
- objects when inspected can merge into one object, the image is distorted.
There are times when a person has false myopia, in which case medication can help.
Another pathology in the work of the visual apparatus is hyperopia. This disease is characterized by perfect vision in the distance and poor vision near. The main symptoms of hyperopia are:
- seeing objects in a fog;
- strabismus is sometimes possible;
- eyes get tired quickly;
Hypermetropia can be functional, normal, and pathological.
What is astigmatism?
An equally complex disease of the visual apparatus is astigmatism. It is often combined with myopia and hyperopia. Astigmatism is characterized by a violation of the sphericity of the lens and cornea. This pathology can be congenital and acquired. Congenital astigmatism is often diagnosed in childhood, and in adulthood it does not affect visual acuity. But this is only in cases where the severity is not higher than half the diopter. When a pathology has more than one diopter, this indicates that vision is deteriorating. The visual apparatus needs urgent treatment. Acquired astigmatism is often the result of corneal scarring.
What is the ideal vision for children?
Eyes are a paired organ that forms before the age of 18. Vision, in turn, can be stable, but it can also change throughout human life. From birth to the first year of life, children experience the formation of the visual system.
After birth, only an experienced specialist can check the pupil’s response to light. By the year children begin to distinguish between familiar objects. Distinguish them in shape and color from each other. After two years of age, a small person begins to see everything more completely and learn to distinguish between objects. When a child goes to kindergarten, the load on the visual apparatus increases. To maintain the ideal vision of the child during this period, it is necessary to take breaks between the loads on the eyes, giving them a rest.
Interesting features of physiology of vision
These are real facts that not everyone knows about;
- In ancient times, people checked their visual acuity in this way: they looked at the sky at night, found the Big Dipper, then examined a small star in the handle of the bucket. This was an indication that the visual apparatus was operating normally.
- The weight of one human eye is approximately 7 g and its diameter is 24 mm.
- Carrots can improve vision. This is absolutely true, vitamin A, which is in this vegetable, helps to maintain the full functioning of the visual apparatus.
- More than 90% of the world's people are born with blue-gray eyes. Closer to the second year of life, eye color forms, which will remain forever.
- Green eyes are the rarest in the world. Only 2% of people are the owners of this color of the iris.
- The most light-eyed nations are considered Poles, Swedes, Finns, and the darkest-eyed nations are Turks and Portuguese.
- In 1% of people on the planet, the color of the iris of one eye is different from the color of the other. Such people, as a rule, possess unusually high intelligence and can be very talented.
- Men blink twice as few as women.
- You cannot sneeze without closing your eyes.