What is refraction?
What is a luminous source and how do we see them?
Why can we see non-luminous objects?
How does light travel?
How are shadows made?
Why do pupils expand in dim light?
Why do pupils get smaller in bright light?
Explain how we see images (eyes)
What do you call the objects that you can only a see a glow of light through something?
What do you call objects that light cannot travel through?
What happens when an object absorbs light?
What is reflection?