Deep in the back of your eye is a layer full of blood vessels. Brown, star-shaped cells live there and help keep things dark inside your eye.
Drag to turn it around. Use the buttons to zoom in and try things from the lessons.
The 3D model can't load right now. Check your internet connection, or try a different web browser.
The back of your eye has three main layers. On the inside is the retina, which senses light. On the outside is the tough white wall. In between is the choroid, a layer packed with blood vessels.
Choroidal melanocytes live in the choroid, tucked between the blood vessels. They are shaped like stars with long arms, and they are filled with brown melanin.
A camera works best when it is dark inside. Your eye is the same.
Scientists think the melanin in these cells soaks up stray light, so it does not bounce around and blur the picture. It may also help protect the back of the eye.
Their cousins in the iris, the colored part at the front of your eye, help give your eyes their color.
Press Soak up light on the 3D model to see the brown cells catch stray light.
Cats have a shiny layer in the back of their eyes. It bounces light back, which helps them see in the dark and makes their eyes glow in photos!