Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Patent
1982-06-30
1985-01-15
Bovernick, Rodney B.
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
351211, 351243, A61B 310, A61B 302
Patent
active
044935390
ABSTRACT:
A method and apparatus for objectively determining the visual contrast sensitivity function of a human subject involves subjecting the vision of the human subject to a plurality of sine wave gratings differing in spatial frequency and contrast levels. As the subject views the grating patterns on a video monitor, the brain wave activity of the subject is detected and steady state Fourier spectra of the activity are recorded. In each spectrum corresponding to a grating pattern of a particular spatial frequency, a visual evoked potential component may be distinguished from noise by adjusting the contrast level of the grating pattern. A contrast threshold used in deriving the visual contrast sensitivity function is identified for each grating pattern of a particular spatial frequency by pinpointing the contrast level at which the visual evoked potential component becomes indistinguishable from noise in the spectrum.
REFERENCES:
patent: 3574450 (1971-04-01), White et al.
patent: 4293200 (1981-10-01), Dobson et al.
Campbell and Maffei, "Electrophysiological Evidence for the Existence _of Orientation and Size Detectors in the Human Visual System," J. of Physiology, 1970, vol. 207, pp. 635-652.
Regan, Evoked Potentials, Chapman & Hull Ltd., 1972, pp. 217, 218, 222-224.
Harris, Atkinson and Braddick, "Visual Contrast Sensitivity of a 6-Month-Old Infant Measured by the Evoked Potential," Nature Dec. 9, 1976, vol. 264, pp. 570-571.
Tyler, Apkarian, Levi and Nakayama, "Rapid Assessment of Visual Function: An Electronic Sweep Technique for the Pattern Visual Evoked Potential," Invest. Ophthelmol. Vis. Sci. Jul., 1979, vol. 18/7, pp. 703-713.
Ginsburg, "Proposed New Vision Standards for the 1980's and Beyond: Contrast Sensitivity," AFAMRL-TR-80-121, Sep., 1981.
Bovernick Rodney B.
Flanagan John R.
Singer Donald J.
The United States of America as represented by the Secretary of
LandOfFree
Method and apparatus for objective determination of visual contr does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for objective determination of visual contr, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for objective determination of visual contr will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1479048