Figure 8.
The effect of intraocular light scatter on the rod contribution to our spectral sensitivity measurements. In order to ascertain whether intraocular light scatter may have affected the calculated contribution of the rod photoresponse to our composite spectral sensitivity function, we calculated the actual stimulus profile striking the retina given our 36 degree stimulus and the effect of intraocular light scatter as specified in CIE collection 135-1999. Panel A is a two-dimensional representation of the actual stimulus profile impinging on the retina and demonstrates the attenuation of our light stimulus for retinal eccentricities greater that +/- 18 degrees from the central fixation. Panel B shows the average pupillary light response over time (n=6) of subject A to an annulus (36°-140 °) which matched the irradiance profile of the light scatter produced by the stimulus used to produce a half maximal PLR in subject A during experiment 1. Note that within 30 seconds of light onset the subject shows no increase in pupilloconstriction over that measured during the baseline measurement interval ten seconds prior to stimulus onset.