The Bedtime Scientist

A question

How do your eyes see?

A calm, true answer. Then, if the wondering keeps going, the whole episode.

The short answer

Light bounces off things, and some of it lands on the retina at the back of your eye, where cells turn it into signals for the brain.

The lens flips the picture on the way in, so the image arrives upside down and your brain quietly turns it the right way up. And your eyes only detect three colours of light. Every other shade you have ever seen, your brain mixes.

Go deeper tonight

Sight: How the World Gets Inside Your Head

The full episode, in one calm voice, with nothing that startles.

The episode

Sight: How the World Gets Inside Your Head

0:00 9:48
Sleep timer

Read the guide for this one in the morning.

This connects to

Light The senses

One idea turns up in many different nights. Follow one and the library starts to join up.