bio

Tapetum lucidum

A reflective layer sitting just behind the retina in many night-active animals. Light that slips past the photoreceptors on the way in strikes this mirror and is bounced back, giving the retina a second chance to absorb the same photons. It is what makes a cat's or a deer's eyes flare in headlights at night - the tapetum throwing back the light it could not use. The cost is a slightly blurrier image, but for an animal that must see in the dark, gathering twice the light is well worth it. Canon attributes exactly this retroreflective layer to the Na'vi.