Color
Vision
Color
Vision Abnormalities
Dichromatic
Vision
In dichromatic vision,
only two of the three so-called primary colors can be perceived by the
observer. Although dichromatic is sometimes called �complete total blindness�
dichromatic individuals perceive as colored nearly everything that a
normal person sees as colored. Their hues, however, generally are quite
different from those seen by the normal individual. Dichromatic vision
is categorized as being protanopia�red-blind, deutranopia�green-blind,
tritanopia�blue-blind.
Protanopia
The most
severe of the common forms of color deficiency. The common name �red
blindness� is accurate since reds are often confused with black, and
red lights that are easily seen by normal viewers may not be visible
to the protanope. In addition, the entire long wavelength portion of
the spectrum is perceived as having only one hue. Thus, red, orange,
yellow, and green all appear to be the same color to a protanope, or
to differ only in saturation and, perhaps in brightness.
| I. |
Trichromates |
Normal
Color Vision |
| II. |
Anamalous
Trichromats
A. Protanomalous
B. Deuteranomalous
C. Tritanomalous
|
Deficient
Color Vision
Red Deficient
Green Deficient
Blue Deficient
|
| III. |
Dichromats
A. Protanopia
B. Deutranopia
C. Tritanopia
|
Partial Color
Blindness
Red Blind
Green Blind
Blue Blind
|
| IV. |
Achromatic |
Complete
Color Blindess |