25 watts
ok this is a strange one.
I was doing an extra drawing tonight, just for practice. Hedda's at work. I had only the little lamp on, on the floor behind me, so the hall was mostly dark.
After a few minutes my face in the mirror went soft. Then it wasn't my face. It was an old woman for a second, and then somebody I've never seen, and then me again. I turned on every light in the flat.
Then I googled it, obviously, and it's a known thing. It's called the strange-face-in-the-mirror illusion. A psychologist called Giovanni Caputo published it in 2010: 50 people sat in a dim room with a 25 watt lamp behind them, about 40 cm from a mirror, staring at themselves for ten minutes. Most of them saw something within the first minute. 66% saw their own face deform, 28% saw an unknown person, 28% saw an archetypal face like an old woman or a child, 18% saw one of their parents. 48% saw monsters.
Something about your brain getting tired of a face it can't stop looking at and filling in the gaps itself.
So I'm normal. Great. It's one o'clock and all the lights are still on.