Vision testing apparatus

Abstract

A vision tester having a casing horizontally adjustable with respect to a base. Inside the casing a rotating drum has a first end rotatably fixed to the casing and a second end unconnected to the casing and having an open portion. An illumination device is removably mounted to the casing and inserted inside the rotating drum through the open portion. The illumination device provides illunination to a plurality of test slides mounted to the surface of the rotating drum. A viewing device is mounted to the casing and provides left and right lenses simulating a far vision of the illuminated test slide. A pair of near vision lenses is rotatably mounted inside the viewing device and may be rotated to overlap the far vision lenses to simulate a near vision of the test slide. Peripheral vision is tested by light provided from an illumination source through fiber optic cables to peripheral vision test locations on the viewing device. A motor mounted within the casing drives the drum in accordance with commands input through a remote control unit. The rotating drum includes first and second cam wheels having registration devices which are detected by microswitches mounted to the casing. Position signals are output to the remote comtrol to display a signal indicating which test slide is being viewed. The test slide includes two glass layers with the test pattern negative and an opal glass sheet interposed therebetween. The test slide is temporarily retained on the rotating drum through a spring-clip mechanism.