Whenever a being, mechanical, magical or meaty, has Glowing Eyes of Doom (or just glowing eyes, Doom Sold Separately) these will flicker and fade out whenever they die. Much like a candle guttering on the last of its wick, death can turn off the literal light in someone's eyes. If the being also has natural Power Crystals in their body (or as the eyes themselves), these too will fade out. Speaking of, since most beings capable of lighting up their peepers aren't human, you can expect that if one is Not Quite Dead they won't just have their eyes open, but blaze brightly.