Lesson 1, Topic 20
Structure & Function of the Eyes
- Cornea– Clear, dome like structure located in the front of the eyes where light enters
- Pupil- Hole in the middle of the iris in which light passes through to the retina.
- Iris – colored part of the eye that surrounds the pupil and controls the amount of light that enters by constricting and dilating
- Lens– located behind the iris and focuses the light onto the retina by changing its shape. Muscles attached to the lens cause it to either become thicker to focus on objects nearby or thinner to focus on objects at a distance .
- Retina – located at the back of the eye and contains cells called photo-receptors responsible for sensing light. Photo- receptors combined with blood vessels form the optic nerve and carry signals to the brain.