Visual test using counter-phase chromatic and achromatic stimuli
US6227668A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2000 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Jul 29, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B3/024
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A novel psychophysical visual test based on the visual response of the eye to alternating chromatic complementary colors or achromatic grays of varying saturation, luminance and/or contrast is proposed for the early detection of glaucoma, and other diseases. In one embodiment, although the luminance level remains constant, the visual stimulus alternates between two complementary or counter phase colors, preferably against a gray background at about 40 times a sec, for example, between blue and yellow. When the colors are alternated in this manner, the visual stimulus appears white or gray to an observer, instead of either blue or yellow. As the saturation is reduced, however, the alternating colors appear grayer, and then eventually cannot be perceived. Persons suffering from glaucoma and other diseases, however, find it more difficult than normal people to distinguish the visual stimulus as the saturation and/or luminance is reduced. Observation thresholds for the visual stimulus can be measured by reducing the saturation of the alternating colors until the visual stimulus disappears against the gray background, and used beneficially to detect for the presence of glaucoma and othe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.