Here are the same ideas in simple words for a 6-year-old:
- Iris: The colored ring of your eye (like blue, green, or brown). It sits around the black circle.
- Pupil: The black dot in the middle. It gets big when it is dark so you can see better and gets small when it is bright to keep out extra light.
- Sclera: The white part that wraps around the eye. It protects the eye like a little shell.
Try this: look in a mirror — the colored part is the iris, the black dot is the pupil, and the white all around is the sclera.