Clinical electroretinography for short wavelength sensitive cones.

We measured electroretinograms (ERGs) for the isolated short-wavelength-sensitive (SWS) cones using a substitution technique. The stimulus was a 5 Hz alternation of 460 nm and 565 nm or 490 nm and 565 nm light of equivalent photopic luminous efficiency. We used a 571 nm narrow-band adaptation field of 7000 td to improve SWS cone isolation and to suppress rod activity. The resulting SWS cone ERG amplitudes were 10-30 microV with latencies of 60-80 msec. A rapid clinical protocol to assess the radiance response function of the SWS cone ERG is described.