Why do we see things?

Imagine you are in a closed room with no windows. The door is closed and there is no way for light to enter the room. It is completely dark. Would you be able to see anything in this room? Why?

Now what is you took a flashlight out of your pocket and turned it on. Would you be able to see the things in the room now? Why?

We need light to see. We see things because light bounces off objects and into our eyes. When light bounces off objects we say that it reflects. 

Examples of reflection

The moon does not make its own light. Light from the sun bounces off the moon and into our eyes. The moon reflects the light of the sun

^{Sunlight is reflected off the moon.}

When you look at yourself in a mirror or another similar surface, you are looking at your reflection. Light reflects off your body to the mirror. Then it reflects into your eyes. This can be seen in the diagram below.

If the surface of a body of water is still enough, it reflects light like a mirror. In the picture below,  we can see the images of objects reflected on the surface of the water.

When we look around us, we are able to see things because light is reflected off objects and into our eyes. As long as there is enough light, we can see things around us very clearly. In the picture below, we can see a flower, the bee on the flower and even the pollen on the bee.