Download Color Blindness - Coosa High School

Color Blindness
“Color Vision Deficiency”
What is it?
• Our eyes determine
Color the wavelength of
a light seen
• Photoreceptors send
Chemical messages to
brain
• Most of us have 3 types
of Cones in the Eye
– Red, Green and Blue
– Called “Trichromatic”
Types of Color Blindness
• Anomalous trichromacy
– Have all 3 cones
– One is defective
– Least severe
• Dichromatic vision
– Missing one cone
• Monochromacy
– All cones are defective
– See only black, white
and gray
• How ColorBlindness
Works
How does a person become
colorblind?
• Most are inherited at
birth
– X – Linked Recessive
•
•
•
•
Aging
Injury to the eye
Side effect of Medicines
Eye Disorders
– Glaucoma, macular
degeneration, cataracts,
diabetic retinapothy
Are dogs Colorblind?
• Dogs are Red/Green
color deficient
• They only have 2
cones in their retina
– Blue and yellow
• Can still perceive a
red ball from a green
one if there is
enough brightness
Testing for colorblindness
• Ishihara Test
– Colored plates
– Diagnose red/green
colorblindess
– Not the most accurate
• Anomaloscope
– Match colors on a screen
by adjusting the light
– Most accurate
– Test online
Color Blindness Testing Cont’d
• Farnsworth Munsell
100 Hue Test
– Arranging colored chips
by order of hue
– Online Test
How a Color Deficient Person sees the
World
• http://colorvisiontestin
g.com/what%20colorbli
nd%20people%20see.ht
m
YOU WILL TAKE THE
ISHIHARA TEST
THE FIRST 3 SLIDES ARE DEMOS TO
SHOW YOU WHAT TO EXPECT
Answer: Everyone should be able to see a circle, star, and square in the demonstration plate.
Colorblind individuals should see the yellow square.
Color normal individuals should see the yellow square and a "faint" brown circle.
Colorblind individuals should see nothing.
Color normal individuals should see a "faint" brown boat.
Continue Ishihara test online
http://www.colourblindness.com/colour-blindnesstests/ishihara-colour-test-plates/
http://www.color-blindness.com/ishihara-38-plates-cvdtest/#prettyPhoto
ISHIHARA TEST YOU CAN DO AT
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