why do things look dark after you stare at something bright (like a lightbulb)?

Question

why do things look dark after you stare at something bright (like a lightbulb)?

In: Biology

Answer 1

In addition to changes in your eye as described in other comments, your brain is fantastically good at adjusting to varying light levels. Think of it as turning up the gain when you are in a dark situation. Not many people realise that even a well lit room is something like 1/10th as bright as a cloudy day outside. Your eye and mostly your brain adapt amazingly well to these changes to the point where you barely notice them, but the adaptation takes time.