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How does vision work?
Quick answer
Vision works by your eyes focusing light onto a layer of light-sensitive cells, which send signals to your brain to build an image. The lens focuses incoming light onto the retina, and the brain interprets those signals as the scene you 'see.
Step by step
- Light enters through the cornea and lens, which focus it.
- It lands on the retina, lined with light-sensing cells (rods and cones).
- Those cells convert light into electrical nerve signals.
- The optic nerve carries the signals to the brain.
- The brain assembles and interprets them into the image you perceive.
People also ask
How do eyes see color?
Cone cells in the retina come in types sensitive to red, green, or blue light; the brain combines their signals into the full range of colors.
Why do some people need glasses?
If the eye focuses light slightly in front of or behind the retina, the image blurs; lenses shift the focus back onto it.
Does the brain do part of seeing?
Very much — the eye captures light, but the brain interprets the signals, fills gaps, and constructs what you actually perceive.
Part of the guide: How Your Body Works →