1. A method of operating data processing apparatus for testing visual acuity and / or visual contrast, which includes displaying characters on the display unit, wherein the displayed symbols are brightness, color and contrast change the brightness, color and / or contrast or something of one or a combination of brightness, color and / or contrast of characters displayed on the display device and changing the period of time display simvolov.2. A method of testing visual acuity and / or visual contrast, which includes displaying characters on the display device of the data processing device, wherein the displayed symbols are the brightness, color, contrast, luminance variation, color and / or contrast or something of one or a combination of brightness, color and / or contrast of characters displayed on the display device changing character display time period and monitoring the patients response to the change in brightness, color and / or contrast and change vremeni.3 period. System testing visual acuity and / or contrast, comprising a data processing device and a display device, wherein the data processing device is arranged to display a symbol on the display device, the displayed characters are brightness, color and contrast wherein said brightness, color and / or contrast, or any of them, or a combination of brightness, color and / or contrast when displaying characters on said screen can be changed and may change the display time period simvolov.4. A method according to claim 1 or 2 or a system according to claim 3, in which the characters display time period is a period during which the characters are displayed on the1. Способ работы устройства обработки данных для тестирования остроты зрения и/или зрительного контраста, включающий в себя отображение символов на устройстве отображения, при этом отображаемые символы, имеют яркость, цвет и контраст изменение яркости, цвета и/или контраста или чего-то одного или сочетания яркости, цвета и/или контраста символов, ото
