glowing eyes
They look cool and animalistic, at least the naturalistic cats'-eye sort do. Glowing eyes look like that to humans because pretty much every other vertebrate on the planet has a reflective layer stuck on the back of their retina called a tapetum lucidum which gives the photoreceptor cells another go at picking up incoming light. Great for night vision, bit blurry for daytime stuff. Some instances of this are done by…
