Figure 1.

(A) Schematic diagram of the effects on light wavelengths (blue and green light) on sleep and arousal states. (B) Melanopsin-deficient mice (Opn4^−/−), as compared to wildtype mice, exhibit blunted responses to non-image forming effects of light, with increased sleep in response to blue light (peak sensitivity around 480 nm) and less sleep induction in response to green light (peak sensitivity around 530 nm). (C) Broadband polychromatic white light potentially impacts on both sleep and wake states, while blue light (short wavelength) actively fosters an enhanced wake state, and green light (longer wavelength) may elicit sleep-promoting effects.