Snellen chart the most common table, used to test visual acuteness. This table contains rows capital letters, called optotipami (test types); font size decreases from row to row from top to bottom.
The major characters are in the top row of the table; they are of such size that they could easily read a person with normal vision from a distance of 60 meters. A person with ordinary vision can easily read and located below the line of letters with the distances 36, 24, 18, 12, 9, 6 and 5 meters respectively.
The man, whose eyes checked, sits down at a distance of 6 meters from the table and closes one eye, while the other starts to read the letter from the table. If he can read only the rows that are located above the line,
which people with normal vision can easily read from a distance of 12 meters, the acuteness of his vision is expressed as 6 / 12. People with normal vision can read from the bottom row of letters from a distance of 6 meters, i.e. normal acuity deemed 6 / 6, many people can read well and the line that well seeing a man reads from a distance of 5 meters.
Smaller versions of this table, based on the establishment of which is the same principle that was used in development of its regular version, can be used to check the passing of man.
Snellen Chart
