Color Vision and Color Deficiencies

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Color VisionandColor Deficiencies

• DeNisha Gammage
• and
• Chertrice Waller
• University of California, Santa Cruz
• Center for Adaptive Optics

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Anatomy of the Eye

• Basic Structures
• Cornea
• Pupil
• Iris
• Lens
• Retina
• Optic Nerve

Courtesy of Jason Porter
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Retina

• Consists of multiple layers
• Light detected by cones and rods
• Rods
• Used for dim conditions
• Cones
• Used in bright conditions
• Used for color vision

http//soma.npa.uiuc.edu/courses/bio303/Images161.
jpg
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Color Vision

• Depends on three types of cones
• S Cone (short wavelength/blue)
• M Cone (medium wavelength/green)
• L Cone (long wavelength/red)

HS
AP nasal
MD
BS
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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

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Types of Color Deficiencies
Normal Color Vision Trichromacy - Three Cone
Types (L, M and S) Color Deficiencies Dichromacy
Two Cone Types Blue Cone Monochromacy One
Cone Type (S only) Rod Monochromacy No Cone
Types, Only Rods
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Dichromatic Color Blindness
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Normal (S,M,L)
Protan or Red/Green (S,M)
Deutan or Red/Green (S,L)
Tritan or Blue/Yellow (M,L)
Courtesy of Hilary OBryan
http//webexhibits.org/causesofcolor/2.html
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Color Deficiency Screening
D- 15
HRR
C-100
Ishihara
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Ishihara

• Pseudoisochromatic plate
• Common test use to screen for color deficiencies
• Detects two types of color blindness
• Protan missing L
• Deutan missing M

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Ishihara Testing Scoring

• Subject is asked to identify numbers

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Ishihara Appearances
Normal Color Vision
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Ishihara Appearances
Protan
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Ishihara - Results

• 24 Subjects
• Male 13
• Female 11
• Normal
• 21
• Protan
• 2 (Male)
• Deutan
• 1 (Male)

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H.R.R

• Pseudoisochromatic plate
• Can detect three types of color blindness
• Protan missing L cone
• Deutan missing M cone
• Tritan missing S cone
• Uses shapes

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H.R.R - Testing Scoring

• Subject describes shapes and location

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H.R.R - Results

• 24 Subjects
• Male 13
• Female 11
• Normal
• 21
• Protan
• 2 (Male)
• Deutan
• 1 (Male)
• Tritan
• 0

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D- 15

• Evaluates color perception
• Can detect three types of color deficiency
• Protan missing L cone
• Deutan missing M cone
• Tritan missing S cone

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D15 - Testing Scoring
Normal Color Vision
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D15 - Testing Scoring

• Normal Pattern
• Protan Pattern

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D15 - Results

• 24 Subjects
• Male 13
• Female 11
• Normal
• 22
• Protan
• 1(Male)
• Deutan
• 1 (Male)
• Tritan
• 0

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C-100

• Can detect two types of color blindness
• Protan missing L cone
• Deutan missing M cone

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C100 Testing Scoring

• Subject moves knob until no flicker
• Test score sheet response and average

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C100 - Results

• 24 Subjects
• Male 13
• Female 11
• Normal
• 21
• Protan
• 2 (Male)
• Deutan
• 1 (Male)

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Results
0
13
0.5
8
87
91.5

• General Population
• Normal- 91.5
• Protan/ Deutan- 8
• Tritan- 0.5

• Our Study
• Normal- 87
• Protan/Deutan 13
• Tritan 0

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Conclusion

• Three cones types used to perceive for color -
  S, M, L
• There is more than one type of color blindness
• We performed four tests
• Ishihara
• HRR
• Tested 24 subjects
• 21 Color Normal
• 2 Protan
• 1 Deutan
• Multiple tests needed
• to confirm color perception
• Color blindness does not
• limit a persons ability, only
• their perceptions

• D-15
• C-100

http//www.firelily.com/opinions/cloor.html
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Acknowledgments

• Monica Piñon
• Emily de la Garza
• Jason Porter
• Kathy Cooksey
• John Martin
• Evan Kirby
• Gene Switkes
• Research Subjects
• CfAO
• COSMOS