Mean (average of all segments) melanin density for each hemiretina (superior and inferior retinas) in control and exposed juvenile and adult rats.

Abbreviations: Brown Norway (BN), Long Evans (LE), postnatal day (P) and days after the light exposure (D). Asterisks identify statistically significant differences (p<0.05) between exposed and control rats at age P60 for each hemiretina (as per one-way ANOVA analysis). Pound signs identify statistically significant differences between exposed adult BN and LE rats (as per one-way ANOVA analysis). Dollar signs identify statistically significant differences between the superior and inferior retinas of LE rats 31 days after the light exposure (as per t-test analysis).