I saw this simple eyeball model that shows how the retina works on Pinterest this morning and so we made one to play around with.

It just simply a magnifying glass, a rolled up piece of black construction paper and a small piece of wax paper or tracing paper.  Directions are here.

When you hold it up to bright light, you can see the image you are aiming it at show up upside down on the wax paper retina.  Cool!  see the upside down tree??

I also showed the kids a refraction trick that I found here.  Start with an arrow on a card then watch the arrow change directions as a jar of water passes in front of it.

We also did it this way.  Science is fun!

I’d like to try this one, too, someday.