Light effects on circadian rhythm collected by rod cells and cone cells and the retinal ganglion cells (RGCs), or it is directly collected by these RGCs. The RGCs use the photopigment melanopsin to absorb the light energy. Specifically, this class of RGCs being discussed is referred to as "intrinsically photosensitive," which just means they are sensitive to light. There are five known types of intrinsically photosensitive retinal ganglion cells (ipRGCs): M1, M2, M3, M4, and M5. Each of these differently ipRGC types have different melanopsin content and photosensitivity. These connect to amacrine cells in the inner plexiform layer of the retina. Ultimately, via this retinohypothalamic
Scanning laser ophthalmoscopy been used in rhesus macaques to track light damage to the macula from particular wavelengths. Additionally, AOSLO provides a greater degree of accuracy for eye tracking than possible before with other techniques. Because of the short scan time involved in AOSLO, eye motion itself represents an obstacle to taking images of the retina. Computational adjustments and modeling have been able to correct for aberrations caused by eye motion between frames. However, by tracking these aberrations based on changes to the retina between pictures, the effect of light on the individual orientation of the cone can be tracked. Research utilizing a