1. Color vision & Color blindness วัตถุประสงค์ ...

2. Color Vision Young-Helmholz theory of color vision in humans:
3 kinds of cones, each containing a different photopigment
maximally sensitive to one of the 3 primary colors
the sensation of any given color being determined by the relative frequency of the impulses from each of these cone systems.

3. The Trichromatic Theory
Any color can be matched by varying the intensities of the three primary lights because every color we see is the result of a ratio of activity among three receptors, each maximally responsive to those three lights
Thus, we sense color through the relative rates of response by three primary of cones
Light absorption by the pigments of the three color-receptive cones of the human retina.

4. Color Blindness Classification Trichromats - have all 3 cone systems
Normal color vision
Protanomaly R cone weak
Deuteranomaly G cone weak
Dichromats - with only 2 cone systems
Protanopia R cone absent
Deuteranopia G cone absent
Tritanopia B cone absent
Monochromats - have only one cone system
Ishihara’s charts

5. Ishihara’s charts