Why is it that when we close our eyes in a room that has the light on, we can see little shapes that seem to move? What

Question: Why is it that when we close our eyes in a room that has the light on, we can see little shapes that seem to move? What are the shapes?
- Keywords:
  light,
  shape
Asked by Resh@science to Chris, Hayley, Jimi on 17 Mar 2016.
- Jimi Wills answered on 17 Mar 2016:
  
  These are the patterns left on your retina (back of the eye) from what you were looking at. They exist because the chemicals used to detect the light are “bleached” i.e. they’ve reacted with the light and now the cells in the eye keep sending messages. Eventually the chemicals are reset and the shapes go away. You only notice when you go from light to dark really quickly, or if you look at something very bright.
- Hayley Moulding answered on 17 Mar 2016:
  
  Oh great question. Even though the light might not be going straight into our eyes we have some left over excited cells at the back of our eyes. When you are in a dark room and you close your eyes, sometimes you can still see shapes too? What happens as the cells need to go back to rest. Once they have, the shapes go away. However, if you close your eyes, push your eyelids onto your eyes (only softly) you might start to see some shapes and lights. These are called ‘phosphenes’. It happens when shapes form without light!

Question: Why is it that when we close our eyes in a room that has the light on, we can see little shapes that seem to move? What are the shapes?