SLAG identifies individual mice possessing functional vision, as validated by DC preference test. Data are pooled together from an age-ranged cohort of 158 B6 mice (57 wild-type, 101 knockout, age range 44–241 days; separate data for individual mice from each genotype appear in Figure 7). (A) Visualization of SLAG and DC performance as a function of age. No evidence for correlation between age and DC preference was observed: SLAG(−) R2 = 0.0012, SLAG(+) R2 = 0.0135 (regression lines not shown). (B) Mean time spent in DC: SLAG(−) = 50%, SLAG(+) = 69% (unpaired two-tailed t-test, means are significantly different, p < 0.0001; two-tailed Mann–Whitney test, p < 0.0001; mean +/− SE bars displayed). Note that every SLAG(+) mouse spent >50% time in DC. (C) Histogram visualization of the data in (B) shows that the SLAG(−) population appears roughly symmetrical, passing the Kolmogorov-Smirnov (KS) test for normality (α = 0.05). (D) Histogram visualization of the data in (B) shows that the SLAG(+) population follows an asymmetrical distribution with respect to DC preference, failing the KS test for normality (α = 0.05).