| A | B |
|---|
| sclera | tough outer layer or "white" of the eye that gives the eye shape |
| cornea | front, outer, transparent layer of the eye |
| iris | colored part of the eye, can change size of pupil |
| pupil | allows light to enter the eye |
| lens | focuses light on the retina |
| retina | innermost layer of the eye that produces an image |
| optic nerve | carries impulses from the retina to the brain |
| vitreous humor | liquid inside the eye to give it a firm shape |
| nearsighted | "long eye"; hard to see distant objects |
| farsighted | "short eye"; difficult to see close objects |
| rods and cones | light-sensitive; layers of cells of the retina |
| rods | sensitive to weak light; black and white vision; used to see at night |
| cones | sensitive to colored light |
| vitamin A | needed for sight; lack of causes night-blindness |
| color blindness | one or more cones are not working properly |
