C O L O R and the human response to light

1. COLORand the human response to light VisionandTheBrain

2. Contents • Introduction: • The nature of light • The physiology of human vision

3. Introduction

4. Short- AC Ultra- wave Gamma X rays Infrared Radar FM TV AM electricity violet -12 -8 -4 4 8 10 10 10 1 10 10 Visible light 400 nm 500 nm 700 nm Wavelength in meters (m) Wavelength in nanometers (nm) 600 nm Electromagnetic Radiation - Spectrum

5. The Interaction of Light and Matter • Some or all of the light may be absorbed depending on the pigmentation of the object.

6. The Physiology of Human Vision

7. The Human Eye

8. cones rods horizontal bipolar amacrine ganglion light The Human Retina

9. The Human Retina

10. Retinal Photoreceptors

11. Cones • High illumination levels (Photopic vision) • Less sensitive than rods. • 5 million cones in each eye. • Density decreases with distance from fovea.

12. 3 Types of Cones • L-cones, most sensitive to red light (610 nm) • M-cones, most sensitive to green light (560 nm) • S-cones, most sensitive to blue light (430 nm)

13. Cones Spectral Sensitivity