Most of the lens in your eye is made of long, thin cells packed side by side. They are so clear that light passes right through them.
Drag to turn it around. Use the buttons to zoom in and try things from the lessons.
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Lens fiber cells are long and skinny, packed together in neat rows like bricks in a wall. Layer after layer wraps around the middle, like an onion.
As each one grows up, it gets rid of its nucleus and most of its other parts. It fills up with clear proteins called crystallins. That makes it see-through.
Together, these cells form the lens. It bends light so the picture lands sharply at the back of your eye.
Tiny muscles pull on the lens to change its shape. That lets you focus on things near and far.
Hold up one finger close to your face and look at it. Now look at something across the room. Your lens just changed shape to focus! Then press Shine a light on the 3D model.
The cells in the middle of your lens were made before you were born. They stay with you your whole life!