Medicine & Health
How does the eye work?
The eye works like a camera: light enters through the cornea and pupil, the lens focuses it onto the retina at the back, and light-sensitive cells there convert it into nerve signals the brain reads as an image.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how the eye works.
Step by step
- 1The cornea and lens bend (focus) incoming light.
- 2The iris adjusts the pupil to control how much light enters.
- 3The retina's rods and cones turn light into electrical signals.
- 4The optic nerve carries those signals to the brain, which builds the image.
Frequently asked questions
- How does the eye focus?
- The lens changes shape to bend light precisely onto the retina — a process called accommodation.
- What are rods and cones?
- Light-sensitive cells in the retina: rods handle dim light and motion, cones handle colour and detail.
- Why don't we see the world upside down?
- The lens projects an inverted image on the retina; the brain flips and interprets it the right way up.