The electroretinographic response to L-and M-cone isolating stimuli was measured at different luminance levels to study the effect of retinal illuminance on amplitude and phase, and how this may influence estimates of L:M ratios in the retina. It was found that the amplitude of L-and M-cone driven responses increases differently with increasing retinal illuminance: L-cone responses increase more quickly than those of M-cones. The L:M ratio does not change strongly with retinal illuminance. The phase of both L-and M-cone driven responses advances with increasing retinal illuminance. There is considerable interindividual variability in the phase difference between the two, but generally M-cone driven responses are phase advanced. © 2011 Cambridge University Press.
- Cone isolation
- L:M ratio