Table 1. Cone ERG parameters.

Genotype	bmax,phot (μV)	amax,phot (μV)	SM (photons·μm-2)-1	SUV (photons·μm-2)-1	SUV/SM
+/+ (n = 7)	200 ± 25	40 ± 5	(1.11 ± 0.1) × 10-4	(4.12 ± 0.4) × 10-4	4.0 ± 0.5
-/- (n = 6)	235 ± 25	35 ± 2	(4.67 ± 1.2) × 10-4	(11.72 ± 2.2) × 10-4	3.1 ± 0.8

The first column indicates the genotype and number of mice tested. The parameters b_max,phot and a_max,phot represent the saturating amplitude of the photopic b-wave and a-waves, respectively. The first value represents the mean and the second value represents the SE. The parameters S_M and S_UV represent the sensitivity of the M- and UV-cone driven systems, measured by determining the amount of light needed to reach a criterion threshold response (20% of the normalized saturated amplitude) and dividing 0.2 by the flash strengths. S_UV/S_M is the ratio of the UV- and M-cone sensitivities. Compared with UV-cones, M-cones require three to four times the amount of light to reach the threshold response.