How the Eye Works
Describe how the eye works: light enters through the pupil, the lens focuses it onto the retina at the back of the eye, and the retina sends signals along the optic nerve to the brain, which interprets the image
What a learner can do afterwards
- Name the main parts: pupil (lets light in), lens (focuses light), retina (detects light), optic nerve (sends signals to brain)
- Describe the sequence: light enters → lens focuses → retina detects → nerve signals brain → brain interprets image
- Explain that the pupil gets bigger in dim light and smaller in bright light to control how much light enters
The lesson
Your eyes work a bit like a camera. Light bounces off the things around you and goes in through a small round opening called the pupil. That is the dark circle you see in the middle of someone's eye.
Just behind the pupil sits the lens. The lens bends the light and focuses it onto the retina, a screen at the very back of your eye. The retina picks up the light and turns it into signals.
Mia looks at a red apple. Light bounces off the apple and enters her pupil. Her lens focuses that light onto her retina. The retina sends a signal down the optic nerve to her brain, and her brain figures out: that is an apple.
Watch how pupils change size. In bright sunlight they shrink to let in less light. In a dark room they grow bigger to let in more light.
Light enters the pupil, the lens focuses it onto the retina, and the optic nerve carries the signal to your brain, which turns it into the picture you see.
Watch it
Where it sits
Learn first
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Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.