1. Optical Illusion

2. Optical Illusion

3. Dragon/ Bending

4. 5 faces in flowers

5. Optical Illusion

7. Let’s look inside the human eye.

8. Lenses and Eyesight
Light entering the eye is focused on the retina by a soft, flexible lens. The human lens is a convex lens so the real image will be upside down. 8

9. An image focused incorrectly on the retina9

10. An image focused correctly on the retina10

11. HOW THE HUMAN EYE
SEES COLOR

12. HOW THE HUMAN EYE SEES COLOR
When light enters your eye, it is focused on a special “screen” at the back of the eyeball. This screen is called the retina.

13. HOW THE HUMAN EYE SEES COLOR
It is made up of two different types of nerves cells, rods and cones. The rods are sensitive to dim light and are useful for night vision. Cones are useful during the daylight and they help to distinguish color because they absorb a different range of wavelengths.

14. HOW THE HUMAN EYE SEES COLOR There are three types of cones:
1. Red cones – absorb mostly red and yellow
2. Green cones – absorb mostly yellow and green
3. Blue cones – absorb mostly blue and violet

15. HOW THE HUMAN EYE SEES COLOR Examples:
When you look at white T-shirt, all three cones are stimulated
When you look at blue jeans, only the blue cone is stimulated
When you look at a yellow shirt, both red cones and green cones are stimulated

16. Light and Color
Type of matter in an object determines the amount of light it absorbs and reflects.

17. Light and Color
Opaque materials – absorbs or reflects all light, you can not see through them
Transparent materials – allow light to pass through, you can see through them
Translucent materials – allow some of the light to pass through; you can not clearly see objects through them

18. Red
Orange
Yellow
Green
Blue
Indigo
Violet
Color Spectrum
Light waves in the visible spectrum arranged from longest wavelength to shortest wavelength.

19. Electromagnetic Spectrum

20. Seeing Color
The color appearance of any object is due to the wavelengths of light that are reflected from the object and picked up by our eyes.

21. Black objects absorb all the colors of the visible spectrum.
Seeing Color Examples
Black objects absorb all the colors of the visible spectrum.

22. Seeing Color Examples
2. Blue jeans appear to be blue because all the colors except blue are absorbed and blue is reflected to your eyes