Dec 24
Dogs and cats are adorable creatures by day, but under the cover of night their eyes seem to shine like demon spawn. That’s the work of the light-reflecting tapetum lucidum, a layer of tissue that sits right behind the retina. As it turns out, that same tapetum lucidum just might be responsible for turning reindeer eyes from gold-hued in the summer to blue-tinted in the winter. Neat!