Abstract

Several studies have evaluated contrast sensitivity of the short-wavelength-sensitive (SWS) cones using chromatic adaptation to produce low contrasts for the middle-wavelength-sensitive (MWS) and long- wavelength-sensitive (LWS) cones, and large contrasts for the SWS cones.^1-3 With sufficiently low MWS and LWS cone contrasts, spatial patterns can only be detected by the SWS cone pathway. These studies have indicated that the SWS cone pathway has poor spatial resolution, a finding which is consistent with histological data on SWS cone density in the primate retina⁴. Wilson, Blake and Pokorny³ recently presented a method for measuring acuity of the SWS cone pathway using black and white square-wave gratings produced on a Macintosh™ computer screen, passed through a blue filter, and optically superimposed on a uniform yellow field. They measured acuity as a function of intensity of the yellow field, and found that acuity decreased as luminance increased from 0 log td to 3.04 log td, then remained constant. Their interpretation of this finding was that for yellow field luminances above 3 log td, acuity is mediated by the SWS cone system. The purpose of the present study is to develop a short version of this method, to determine the variability of SWS cone acuity in normals, and to evaluate the usefulness of the method for detecting SWS cone loss in patients with retinitis pigmentosa and good Snellen acuity.

© 1988 Optical Society of America