How We See for Kids: Light, Eyes and the Brain (Grade 4 and 5 Science)

Hi, I'm Luna from DoodleBeez. How do you see the world around you? It is a team effort between light, your eyes and your brain. Today we will follow light on its journey.

First, we need light. Light comes from sources like the sun, a lamp or a flame. In a completely dark room, you cannot see anything, because there is no light to enter your eyes.

Most objects do not make their own light. Light from a source hits the object and bounces off. Some of that reflected light travels into your eyes. That is how you see the object.

Light enters the eye through the pupil, the dark hole in the middle. The colored part around it, the iris, makes the pupil bigger in dim light and smaller in bright light.

Behind the pupil is the lens. It bends the light and focuses it onto the retina, a layer at the back of the eye. The image on the retina is actually upside down!

The retina turns light into signals. The optic nerve carries those signals to the brain. The brain makes sense of them, flips the image right side up and tells you what you are seeing.

Now it's your turn. Is this true or false? We see a book because light shines out of our eyes onto it. Pause and try. False. Light reflects off the book and travels into our eyes.

Great job! Remember, light reflects off objects into your eyes. The lens focuses it on the retina, and the brain makes the picture. Practice how we see in the Science Lab at doodlebeez.com. See you next time!