Patent attributes
An optometric apparatus (2) includes a rotary prism (136a, 136b) disposed in front of the eye (E), for adding a prism degree to the eye (E); a rotation device including a pulse motor (181, 184) and a rotation transmitting mechanism (146, 147, 176, 176a, 177, 177a, 178, 179, 182, 183, 185, 186) for transmitting rotation of the pulse motor to the rotary prism, the rotation device being adapted for rotating the rotary prism to change the prism degree; a command device (43a, 43b) for generating a command signal to start and stop the rotation of the rotary prism; and a control unit (60) for controlling the rotation device to drive the pulse motor to rotate at a speed of 5 pulses/sec. or more when the control unit receives the rotation start command signal until when receives the rotation stop command signal, and, to change the prism degree at a speed of 0.1 to 1.0 prism/sec.