Post on 06-May-2018
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Color Vision and Color Color Vision and Color DeficienciesDeficiencies
Jane Jane PhilippsPhilipps and and NallelyNallely GarciaGarcia
OverviewOverview
•• How Do We Perceive Color?How Do We Perceive Color?
•• Color DeficienciesColor Deficiencies
•• Tests for Color DeficienciesTests for Color Deficiencies
•• Our Test ResultsOur Test Results
•• How Do Color Deficiencies Limit People?How Do Color Deficiencies Limit People?
How Do We Detect and See Light?How Do We Detect and See Light?
Fovea• Light enters eye
• Focused by cornea and lens onto back of retina
• Photoreceptors absorb light
• Light is transformed into electrical signals
• Signals sent to brain via optic nerve
RodsRodsFor Night VisionFor Night Vision> 90 % of Photoreceptors> 90 % of PhotoreceptorsNone in FoveaNone in Fovea
ConesConesFor Day VisionFor Day Vision< 10 % of Photoreceptors< 10 % of PhotoreceptorsConcentrated in FoveaConcentrated in Fovea
Two types of Photoreceptors in RetinaTwo types of Photoreceptors in Retina
Rod Cone
http://www.lightenergysource.com/LES%20-%20Rods%20&%20Cones.jpg
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/imgvis/rcdist.gif
Cones are Responsible for Color VisionCones are Responsible for Color Vision
Three Types:
Long (L, Red) 62%
Medium (M, Green) 31%
Short (S, Blue) 7%
0
20
40
60
80
100
120
340 380 420 460 500 540 580 620 660 700Wavelength (nm)
Abs
orba
nce
S Rod M L
Images of Cones in the Fovea
* A. Roorda & D.R. Williams, Nature 1999H. Hofer, J. Carroll, D.R. Williams
*
*
*
5 arcmin
16:1
1:3
How Do People Get Color Deficiencies?How Do People Get Color Deficiencies?
Genetic• Color Deficiencies are recessive traits carried on X chromosome
• Females have XX, Males have XY – Males have a greater chance
• 8 % of Caucasian males have a Red/Green Color Vision Deficiency
• 15 % of Caucasian females carry Color Vision Deficiency genes
Acquired• Eye Disease, Drug Use, Overexposure to Lead or Mercury, Injury to
eye or brain
• Equal Chances for Males and Females
Types of Color Deficiencies
Normal Color VisionTrichromacy - Three Cone Types (L, M and S)
Color DeficienciesAnomalous Trichromacy
Three Cone Types - One Has Altered SensitivityDichromacy
Two Cone TypesBlue Cone Monochromacy
One Cone Type (S only)Rod Monochromacy
No Cone Types, Only Rods
DichromacyDichromacy and Anomalous and Anomalous TrichromacyTrichromacyRed/Green Color Deficiencies
Protan – L Cone Deficiency• Protanomalous – altered sensitivity• Protanope – missing
Deutan – M Cone Deficiency• Deuteranomalous – altered sensitivity• Deuteranope – missing
Blue/Yellow Color Deficiency
Tritan – S Cone Deficiency• Tritanope – missing
Normal (S,M,L) Protan or Red/Green (S,M)
Deutan or Red/Green (S,L) Tritan or Blue/Yellow (M,L)http://webexhibits.org/causesofcolor/2.html
Screening Tests for Color DeficienciesScreening Tests for Color Deficiencies
AO-HRR
C100
ISHIHARAD15
AOAO--HRR HRR –– PseudoisochromaticPseudoisochromatic PlatesPlates
•• Tests for Tests for ProtanProtan, , DeutanDeutan, , TritanTritan
•• Subject must identify and Subject must identify and trace shapes on platestrace shapes on plates
AOAO--HRR ResultsHRR Results
•• 20 subjects tested20 subjects tested•• 10 males10 males•• 10 females10 females
•• 1 1 protanprotan (male)(male)•• 1 1 deutandeutan (male)(male)•• 18 normal18 normal
•• 8 males8 males•• 10 females10 females
Ishihara Ishihara –– PseudoisochromaticPseudoisochromatic PlatesPlates•• Tests for Tests for ProtanProtan, , DeutanDeutan•• Subject must read numbers they seeSubject must read numbers they see
Normal Color Vision
Ishihara Ishihara –– PseudoisochromaticPseudoisochromatic PlatesPlates•• Tests for Tests for ProtanProtan, , DeutanDeutan•• Subject must read numbers they seeSubject must read numbers they see
Protan Color Vision
Ishihara ResultsIshihara Results
•• 22 subjects tested22 subjects tested•• 10 males10 males•• 12 females12 females
•• 1 1 ProtanProtan (male)(male)•• 1 1 DeutanDeutan (male)(male)•• 20 normal20 normal
•• 8 males8 males•• 12 females12 females
DD--1515
•• Tests for Tests for ProtanProtan, , DeutanDeutan, , TritanTritan
•• Subject must Subject must arrange colored arrange colored disks by huedisks by hue
DD--15 Results15 Results
•• 21 Subjects tested21 Subjects tested•• 10 males10 males•• 11 females11 females
•• 1 1 ProtanProtan (male)(male)•• 20 normal20 normal
•• 9 males9 males•• 11 females
Normal
11 females
Protan
C100C100•• Tests for Tests for ProtanProtan, , DeutanDeutan•• Subject must find spot with least amount of Subject must find spot with least amount of
flickerflicker
C100 ResultsC100 Results
•22 Subjects
•11 males
•11 females
•1 Protan (male)
•21 Normal
•10 males
•11 females
C100 Test Results
012345678
-5 -4 -3 -2 -1 0 1 2 3 4 5
C100 Average Score
# of
Sub
ject
s
Protan DeutanNormal
How Can Color Deficiencies Limit Humans?How Can Color Deficiencies Limit Humans?Careers
Bus Driver, Firefighters, Police Officers, Paint Makers, Doctors, Chemists, Decorators, Computer Programmers
SchoolAffects Reading and Math Skills
Which Flask Contains the Pink Solution?
ConclusionsConclusions• Cone Photoreceptors are Used to Perceive Color
Long (L), Medium (M), and Short (S) Wavelength Sensitive
• Three Main Color Deficiencies
Protan (Missing or Altered L Cone)
Deutan (Missing or Altered M Cone)
Tritan (Missing or Altered S Cone)
• Color Deficiency Screening Tests and Results
1 Protan (AO-HRR, Ishihara, D-15, C-100)
1 Deutan (AO-HRR, Ishihara)
• Need to Conduct Several Tests for Accurate Diagnosis