OPTOM FASLU MUHAMMED
Colorvision: Is the capacity of an organism or
machine to distinguish objects based on the
wavelengths or frequencies of the light they
reflect or omit.
Colorvisionis a function of cones and better
appreciated in photopic vision.
Hue
Is the identification of color.
Brightness
Is the intensity of color.
Saturation
Is the purity of a color.
THEORIES OF COLORVISION
Also called as YOUNG-HELMHOLTZ THEORY.
The existence of three kinds of cones, each
containing a different photo pigments and
maximally sensitive to one of three primary
colors RED,GREEN and BLUE.
RED sensitive cone pigment /ERYTHROLABE or
long wavelength sensitive (LWS)
GREEN sensitive cone pigment /CHLOROLAB or
medium wavelength sensitive (MWS)
BLUE sensitive cone pigments /CYANOLAB or
short wave length sensitive.
Therefore, color vision is
the consequence of
unequal stimulation of
the 3 types of cones. In
a specific ratio.
Example : If you stimulate
all 3 types of cones
about equally the result
is white or no color.
By HERING
Some colors appear to be mutuallyexclusive.
Red with green
Yellow with blue.
COLORBLINDNESS
An individual with normal color vision is known as
TRICHOMATE.
In color blindness, faculty to appreciate one or
more primary colors is either defective
(anomalous) or absent (anopia)
It may be congenital or acquired
X –linked recessive inherited condition.
Affecting males(3-4%) more than females(0.4%)
It may be
Dyschromatopsia
Achromatopsia
Color confusion due to deficiency of mechanism to
perceive colors.
It can be classified in to :-
Anomalous Trichromatism
Dichromatism
The mechanism to appreciate all the three primary
color is present but is defective for one or two of
them.
Protanomalous:- defective red color
appreciation.
Deuteranomalous:-defective green color
Tritanomalous:- defective blue color
One of the three primary color is completely
absent. such individual are called Dichromate.
Protanopia :-complete red color defect
Deutreranopia :-complete green color defect.
Tritanopia :- complete blue color defect.
It is an extremely rare condition.
CONE MONOCHROMATISM
ROD MONOCHROMATISM
Presence of only one color and thus the person is
truly color blind.
Visual acuity of 6/12 or better.
Complete or incomplete
Total color blindness
Day blindness (Visual acuity is about 6/60)
Nystagmus
Funds is usually normal.
Damage to macula or optic nerve.
Associated with a central scotoma or decreased
visual acuity.
These are the colours of the rainbow and also what
they would look like if you were colour blind
This is what a normal person would see as the
colours of the rainbow
This is the same picture viewed by someone with
protanopia.
This is the same picture viewed by someone with
deuteranopia
This is the same picture viewed by someone with
tritanopia
This is the same picture viewed by someone with
Monochromacy which Is full colour blindness
THANK YOU