1. EYE
Kim Lachler
Updated 2015
NCES: 6.P.1.2

2. How we see.
Your eyes are designed to detect the visible light of the electromagnetic spectrum
The_Human_Eye.mov

3. How we see. Light refracts (bends) as it passes through the cornea.
The membrane that protects the eye.
(Note: the white part of the eye is called the sclera)

4. How we see. Light then pass through the pupil. Pupil
The opening in the eye.
It appears black
It does not change size.

5. How we see. The size of the pupil is controlled by the iris. Iris
It is the colored part of the eye.
It gets smaller when it is dark to allow more light to enter the eye.

6. How we see.
The eye focus an image on the back of the eye with the lens.
Lens
Convex shape.
Refracts light to the back of the eye.

7. How we see. Light is detected by receptors in the retina. Retina
Back surface of the eye
Contains rods and cones.
Rods are on the outer surface and detect shadows and movement.
Cones are on the center surface and detect color.

8. How we see.
It is converted to electrical signals carried to the brain by nerves.
Optical nerve
Carries the information to the brain.

9. Eye Problems Nearsightedness
Person is able to see things clearly that are close but not far.
Result of the lens focuses objects in front of the retina instead of on it.
Concave lens glasses correct the problem. (Curved in)

10. Eye Problems Farsightedness
Person is able to see things clearly that are far but not close.
Result of the lens focuses objects behind the retina instead of on it.
Convex lens glasses correct the problem. ( Curved out)

11. Eye Problems Color Blindness The cones do not work properly.
Usually have the most trouble with red and green.
5-8% of all men and .5% of all women have it.

12. Bibliography
Holt, Rinehart, Winston, North Carolina Holt Science & Technology, Holt, Rinehart, Winston, Orlando, 2005
Google images, googleimages.com, accessed 2011