Figure 4. Action spectrum for melatonin suppression compared to the rod and cone absorption spectra.

Action spectrum for melatonin suppression corrected for lens filtering (•) compared to the known rod and cone photoreceptor absorption spectra (from Dartnall et al. 1983). Short wavelength sensitive (S) cone absorption spectrum (λ_max 419 nm); rod absorption spectrum (λ_max 496 nm); medium wavelength sensitive (M) cone absorption spectrum (λ_max 531 nm); and long wavelength sensitive (L) cone spectrum (λ_max 558 nm).