It is dark in the womb—but not that dark. Human flesh isn’t fully opaque, so some measure of light will always pass through it. This means that even an enclosed space like a uterus can be surprisingly bright. “It’s analogous to being in a room where the lights are switched off and the curtains are drawn, but it’s bright outside,” says Vincent Reid from the University of Lancaster. “That’s still enough light to see easily.”  Click her for full text Fetuses Prefer Face-like Images.