HOW WE SEE THINGS
QCA Unit number 6F

WHAT'S THE BIG IDEA?

It was only a few hundred years ago that it was finally discovered how we see things. Before that, it was believed that we saw things because rays shot from our eyes, maybe bouncing back to our eyes or joining with rays of light landing on the object.

We see things because our eyes are receivers of light. Light travels to our eyes. The light enters our eyes. We see the light reflected from an object.

Light reflected from a shiny surface can reflect an image - a picture. This is how mirrors work.

If light is blocked by an object, a shadow is formed. Opaque objects make strong shadows, because they let no light through them. Transparent objects let almost all the light through them. But even they cast a slight shadow.