tapetum lucidum | noun

tapetum lu·​ci·​dum -ˈlü-si-dəm // (Latin for 'bright tapestry’)

: a layer of crystalline tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light available to the photoreceptors (although slightly blurring the image).