Mentor O & O, Inc.

Mentor Corporation

Morey H Waltuck

Robert Nelson McKnight

Jack T Holladay

Robert Mcknight

Eliezer Peli

Kurt Paul Tolksdorf

John Donal Starr

A visual acuity tester based on a personal computer is provided that is capable of displaying visual acuity test characters at varying sizes on a monitor. The visual acuity tester antialiases the test characters to overcome the effects of staircase distortion. Preferably, the visual acuity tester performs unweighted area sampling antialiasing. The visual acuity tester also centers the test characters relative to the pixel array of the monitor to improve the appearance of the test characters. The test characters can be centered relative to either the center of a pixel or the corner of a pixel (a pixel coordinate). Test characters can also be centered relative to a pixel center in one dimension and a pixel coordinate in the other dimension.

Visual acuity tester with improved test character generation

An improved visual acuity tester is disclosed that is adapted both to measure the visual acuity of a patient and to function as an integral optical prescription calculator. The visual acuity tester essentially includes a display monitor for displaying visual acuity targets, electronic means for generating a plurality of visual acuity targets to be displayed on the monitor, and a hand-held remote control unit provided with a display unit and a keyboard coupled to the electronic means for controlling the display on the monitor and for performing prescription calculations. The visual acuity targets are created by toggling on/off the electronic means when horizontally scanning the lead lines of screen memories of the targets. Preferably, the electronic means includes a dynamic memory having two screens of memory: an active screen and an inactive screen. The active screen is displayed on the monitor and the inactive screen is being erased, both being constantly accessed at short intervals for memory refresh and erasure. Preferably, the visual acuity tester is provided with a contrast control for low contrast testing. The visual acuity tester is adjustable for straight refractory distances from about ten to about twenty feet in length. With a mirror, it also can be fitted to a shorter refractory lane.

Visual acuity tester

A visual function tester with binocular vision testing capabilities is disclosed, which includes a video display monitor and optical means, such as stereo vision glasses, to control the patient's viewing of the display. The opening and closing of the apertures of the glasses is synchronized to the display of a variety of visual acuity images. Certain images are made visible to each eye but not visible to the other, and certain images are displayed such that they appear out of the plane of the images. Methods for use of the apparatus are also disclosed.

Visual function tester with binocular vision testing

A brightness acuity tester to assess functional visual acuity in bright light conditions and to test for recovery of visual activity after photostressing the retina is disclosed. The tester essentially comprises a device closed in one direction and open in an opposite direction, an aperture provided in the device, a source of illumination mounted within the device, a plug designed removably to be positioned in the aperture to seal the same, and a power source coupled to the source of illumination via a switch. Preferably, the source of illumination is provided with anintensity control and the power source with a voltage regulator. Preferably, the device comprises a reflector having diffusely reflecting characteristics. Preferably, the power source is a battery, making the tester a hand-held one.

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Sharon, MA, United States of America

Morey H Waltuck