US Patent 7537343 Optotype presenting apparatus

An optotype presenting apparatus for testing a visual function of an eye of an examinee comprises: a display unit including a display which displays various optotypes by controlling a number of pixels and a memory in which the optotypes to be displayed on the display are stored; an operation unit for inputting a selection signal to select an optotype to be displayed on the display; and a display control unit for switching an optotype to the selected optotype in such a manner as to cause the optotype displayed before switching to disappear in response to the selection signal and then display the selected optotype after 0.05 second to 1.0 second from the disappearance of the optotype displayed before switching.