Abstract: An optotype presenting apparatus, by which red and green optotypes can be visually perceived independently by right and left eyes even if red filters and/or green filters have different wavelength transmission characteristics, comprises a color display, a unit having a switch for selecting a test chart including visual acuity and red-green binocular visual performance test charts, wherein the binocular test chart includes the optotypes and is used in the test performed with the filters in front of the eyes, a memory storing color adjustment data in which at least one of color tones of the optotypes is varied with the characteristic of one of the filters, a unit for inputting a signal for selecting one of the data, and a unit controlling the display to display the selected chart and adjusting the tones by reading the selected data from the memory when the binocular test chart is selected.

Abstract: A visual acuity testing apparatus capable of performing visual acuity testing under substantially uniform conditions even when a test distance and an installation distance vary has a projection optical unit including a disk whereon a chart is placed, an illumination light source, and variable projection lenses which are moved so as to change an image-forming position and an image size of an image of the chart, an input unit into which an installation distance between the screen and the visual acuity testing apparatus and a test distance between the screen and an examinee are inputted, a projection lens driving unit which moves the variable projection lenses based on the installation distance and the test distance, and a light intensity adjusting unit which adjusts light intensity based on the installation distance and the test distance so that brightness of the chart image falls within a predetermined reference range.

Abstract: An optotype presenting apparatus which presents an optotype for visual acuity test, the apparatus comprises: a display that is illuminated by a backlight and includes a light intensity changing device which changes backlight intensity; a background luminance selecting device which selects background luminance of the optotype among a plurality of preset levels, in which background luminance at each level corresponds to standard light intensity changing data in a changeable range determined by the light intensity changing device; and a correction device which corrects the standard light intensity changing data in the background luminance selecting device, the correction device including: an input device which inputs the background luminance measured by an illuminance meter, the measured background luminance being background luminance obtained when the light intensity changing device is operated based on the preset light intensity changing data; and a calculation device which determines correction light intensit

Abstract: 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.

Abstract: An optotype presenting apparatus for presenting an optotype to be used for testing a visual function of an eye of an examinee, the apparatus comprises: a display unit including a memory in which a plurality of optotypes is stored and a display on which at least one of the stored optotypes is displayed; an operation unit by which at lest one of the stored optotypes to be displayed on the display is selected; a pilot lamp placed to be visible by the examinee who is in front of the display; and a control unit which turns on the pilot lamp when the display unit is powered on and the display is in an off-state, and turns off the pilot lamp when the display unit is powered on and the display is in an on-state.

Abstract: A visual function test apparatus for testing a visual function by presenting an optotype to an examinee's eye is disclosed. This apparatus includes a first half mirror disposed on a projection optical axis of light of the optotype; an illumination light source having a projection optical axis which is made substantially coaxial with the projection optical axis of the optotype light by the first half mirror; a concave mirror which reflects an illumination light from the illumination light source and the optotype light; a second half mirror disposed between the first half mirror and the concave mirror, the second half mirror reflecting the optotype light and the illumination light both reflected by the concave mirror toward the examinee's eye; and a control section which changes a ratio between a light quantity of the optotype light and a light quantity of the illumination light in accordance with a predetermined contrast ratio.

Abstract: A visual acuity examination apparatus for examining a visual acuity of an examinee by presenting an optotype to the examinee includes an optotype presenting unit which selectively presents at least one of a plurality of comparison optotypes expressed in geometrical series, the optotypes being provided to be plural in number for each visual acuity value, an input unit with which a distinction answer of the examinee with respect to the presented optotype is input, a storage unit in which an examination program which sequentially determines an optotype to be next presented based on whether the distinction answer with respect to the presented optotype is right or wrong is stored, a control unit which controls the optotype presenting unit in accordance with the examination program, and a processing unit which determines a visual acuity value of the examinee from a percentage of right answers in the distinction answers with respect to an optotype for a visual acuity value.

Abstract: A visual acuity testing apparatus comprises a casing having at least one test window which an examinee looks into, and at least one optotype presented inside the casing which is disposed in such a position that its optotype plane is tilted relative to a datum plane orthogonal to an axial line connecting the test window to an optotype presentation position in order to prevent that light entered through the test window and reflected from the optotype plane, passes through he test window again.

Abstract: A visual function test apparatus for testing a visual function by presenting an optotype to an examinee's eye is disclosed. This apparatus includes a first half mirror disposed on a projection optical axis of light of the optotype; an illumination light source having a projection optical axis which is made substantially coaxial with the projection optical axis of the optotype light by the first half mirror; a concave mirror which reflects an illumination light from the illumination light source and the optotype light; a second half mirror disposed between the first half mirror and the concave mirror, the second half mirror reflecting the optotype light and the illumination light both reflected by the concave mirror toward the examinee's eye; and a control section which changes a ratio between a light quantity of the optotype light and a light quantity of the illumination light in accordance with a predetermined contrast ratio.

Abstract: A visual acuity examination apparatus for examining a visual acuity of an examinee by presenting an optotype to the examinee includes an optotype presenting unit which selectively presents at least one of a plurality of comparison optotypes expressed in geometrical series, the optotypes being provided to be plural in number for each visual acuity value, an input unit with which a distinction answer of the examinee with respect to the presented optotype is input, a storage unit in which an examination program which sequentially determines an optotype to be next presented based on whether the distinction answer with respect to the presented optotype is right or wrong is stored, a control unit which controls the optotype presenting unit in accordance with the examination program, and a processing unit which determines a visual acuity value of the examinee from a percentage of right answers in the distinction answers with respect to an optotype for a visual acuity value.