Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Subjective type
Patent
1995-10-24
1997-01-21
Dang, Hung
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Subjective type
351239, 351245, 351246, A61B 302, A61B 300
Patent
active
055963790
ABSTRACT:
A portable visual acuity testing system and method is used to measure the visual acuity of a person being tested. The portable visual acuity testing system includes a portable visual acuity testing structure and a plurality of interchangeable image display cards adapted to be engaged with the structure. Each image display card includes one or more images, such as a Snellen letter or Allen figure, of a predetermined size. A distance measurer, such as an ultrasonic distance measuring device is included within the portable visual acuity testing structure. When the portable visual acuity testing device is positioned at a distance from the person being tested at which the person can see or visually recognize the image, the distance measurer is activated to automatically and accurately measure the distance to the person being tested. The portable visual acuity testing device includes built in circuitry for calculating a visual acuity level based on the measured distance and the predetermined size of the image, such as a "Snellen Equivalent," which can then be displayed on the portable visual acuity testing device.
REFERENCES:
patent: H293 (1987-06-01), Task et al.
patent: 4408846 (1983-10-01), Balliet
patent: 4764006 (1988-08-01), Hamano et al.
patent: 5237351 (1993-08-01), Kohayakawa
patent: 5398085 (1995-03-01), Hofeldt
patent: 5420652 (1995-05-01), Fujieda
patent: 5471262 (1995-11-01), Trokel
Bourque Daniel J.
Carroll Kevin J.
Dang Hung
LandOfFree
Portable visual acuity testing system and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Portable visual acuity testing system and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Portable visual acuity testing system and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2327983