Understanding how the eyes detect light without involving vision

Retinal degenerate mice lacking melanopsin or cryptochromes show contributions from both outer and inner photoreceptors to non-visual photoresponses.

• Intrinsically photosensitive retinal ganglion cells send signals about light conditions to brain areas involved in circadian rhythms and pupil responses.
• The specific phototransduction systems used by these cells remain unidentified.
• Melanopsin and cryptochromes are suggested as possible photopigments for these cells.
• Findings indicate that both melanopsin and cryptochromes are important for non-visual responses to light.

Simplified