This document discusses color vision and color vision testing. It provides information on: 1. Theories of color vision such as Young-Helmholtz theory and opponent-process theory. 2. Types of color vision deficiency including anomalous trichromacy, dichromacy, and monochromacy. 3. Clinical tests used to assess color vision like Ishihara plates, Farnsworth panels, and anomaloscopes. 4. The document provides details on how these various color vision tests work and what results would indicate normal or deficient color vision.

1. Shashi Bhushan
Assistant Professor BVP
Color vision
&
its test
9/28/2022

2. • COLOR VISION
• COLOR VISION THEORIES
• COLOR VISION DEFECTS
• COLOR VISION TESTS
INTRODUCTION
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3. Color vision
• Perception of color by the pigments of cone
according to the genetic code
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Jennifer Birch Diagnosis of
defective color vision pg 17

4. Characteristics of color vision
• Hue :- capacity of the eye to discriminate
between the adjacent wavelength
• Brightness:- depend on luminous flux
• Saturation :- it measure the minimum
quantity of given wavelength that must be
added to the white light for change in
appearance to be detected
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Jennifer Birch Diagnosis of
defective color vision pg 18

5. Theories of color vision
1. Additive color theory
2. Subtractive color theory
3. Thomas Young theory
4. Young Helmholtz theory
5. Herring's opponent theory
6. Tetrachromatic theory
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6. Additive color theory
• Based on 3 primary color – red , green & yellow
• Mixture of 2 primary color give rise to secondary
color
A+B=Y (Yellow)
A+C=M (Magenta)
B+C= C (Cyan)
A+B+C=W (White)
W
RED
GREEN
BLUE
M C
A
C
B
Y
9/28/2022 Paul L. Pease- CR Borish’s, 250

7. Subtractive color theory
CYAN
M
A
G
E
N
T
A
BLUE
RED
YELLOW
G
R
E
E
N
BLACK
• Mixing of paints, dyes, inks & natural colorant to
create a range of colors
• Color mixture absorbing some wavelength of light
& reflecting others
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Paul L. Pease- CR Borish’s, 251

8. Thomas Young theory
• For every color one nerve fiber present in the
retina
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Jennifer Birch Diagnosis of
defective color vision pg10

9. Young Helmholtz theory
• 3 cone photoreceptors on the retina which is
sensitive to different wavelength
Erythropsin
Chloropsin
Cyanoipsin
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Jennifer Birch Diagnosis of
defective color vision pg 10

10. Herring’s opponent theory
• Based on 4 primary colors – Red, Green, Blue &
Yellow arranged in opponent pairs
Red – Green
Yellow -Blue
White- Black
9/28/2022 Paul L. Pease- CR Borish’s, 259

11. Tetrachromatic theory
• Based on 4 primary colors – Red, Green, Blue &
Yellow
• Yellow is not a combination of Red & Green
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Jennifer Birch Diagnosis of
defective color vision pg 11

12. Color vision deficiency
• Lack of any color sensation
• It effects either the photoreceptor or the channels
results in the ability to discriminate color
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Jennifer Birch Diagnosis of
defective color vision pg15

13. Consequences of color deficiency
• The retina is made of rods and cones .
• The rods give us night vision
• Cone give us color vision & day vision
• Each cone contains light sensitive pigments.
• Gene contains coding instruction for these
pigments .
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Jennifer Birch Diagnosis of
defective color vision pg15

14. Consequences of color deficiency
• If the coding instructions are wrong the
wrong pigments will be produced.
• And the cone will be sensitive to different
wavelength of light.
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Jennifer Birch Diagnosis of
defective color vision pg 15

15. Types of color vision deficiency
1. Congenital color vision deficiency
2. Acquired color vision deficiency
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Jennifer Birch Diagnosis of
defective color vision pg 17

16. Trichromatism:all three systems are present
Dichromatism: one system is absent.
Monochromatism:two system are absent
The three systems are :
Red ,Green & Blue.
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Jennifer Birch Diagnosis of
defective color vision pg 27

17. Classification of color Vn defect
Congenital Acquired
Anomalous
trichromatism
Dichromatism Monochromatism
Protenomaly
Deuteranomaly
Tritanomaly
Protanopia
Deutranopia
Tritanopia
Rod monochromatism
Cone monochromatism
Type 1 R-G
deficiency
Type 2 R-G
deficiency
Type 3 B-Y
deficiency
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18. Anomalous trichromatism
• People with anomalous trichromat vision
use all three color receptors but reception of
one pigment is misaligned.
1. Protanomaly: reduced red sensitivity
2. Deuteranomaly: reduced green sensitivity
3. Tritanomaly: reduced blue sensitivity.
9/28/2022
Jennifer Birch Diagnosis of
defective color vision pg 27

19. Dichromatism
• People with dichromatism use only two of the
three visual pigments.
1. Protanopia: unable to receive red.
2. Deuteranopia: unable to receive green.
3. Tritanopia: unable to receive blue.
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Jennifer Birch Diagnosis of
defective color vision pg 27

20. Monochromatism
• Two type
1. Rod monochromatism- decrease visual acuity
nystagmus, central scotoma & photophobia
2. Cone monochromatism- normal visual acuity
9/28/2022 Paul L. Pease- CR Borish’s,268

21. Acquired color vision defect
• There are 3 types
1. Type -1 red-green deficiency
2. Type -2 red-green deficiency
3 . Type -3 blue-yellow deficiency
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Jennifer Birch Diagnosis of
defective color vision pg 110

22. Colour appearance
NORMAL
PROTANOPES
DUETRANOPES
TRITANOPES
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23. Clinical test for color vision assessment
1. Pseudo-isochromatic plate
• Ishihara color Vn chart
• AOHRR plate
2. Arrangement test
• Farnsworth Munsell – 100 hue test
• Farnsworth D-15 test
3. Anamoloscope
• Nagel’s anamoloscope
4. Occupational test
• Lantern test
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24. Ishihara color vision chart
• Based on the color confusion
(Pseudoisochromatism)
• Each pseudoisochromatic plate is crowded
with colored spots
• Use to determine red -green deficiency
• Available in 16, 24 & 38 plates
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Jennifer Birch Diagnosis of
defective color vision pg 56

25. 1. Demostration plate (1)
• 12 no. plate
• Both normal & color Vn defect pt. can read
2. Transformation plate (2-9)
• 8, 6, 29, 57, 5, 3, 15 & 74
• Normal person can read correctly
• Red – green deficiency person can read them as
3, 5, 70, 35, 2, 5, 17 & 21
• Total color Vn defect person can’t read any no.
Ishihara color vision chart
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Jennifer Birch Diagnosis of
defective color vision pg 56

26. 3. Vanishing plate (10-17)
• 2, 6, 97, 45, 5, 7, 16 & 73
• Normal person will read correctly
• Red– green deficiency person not able to read
( either completely or incompletely )
• Total color Vn defect person can’t read any no.
Ishihara color vision chart
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Jennifer Birch Diagnosis of
defective color vision pg 56

27. 9/28/2022
4. Hidden plate (18-21)
• 5, 2, 45 & 73
• Normal & total color Vn defect person not able
to read any no.
• Red –green deficiency person will read correctly
Ishihara color vision chart
Jennifer Birch Diagnosis of
defective color vision pg 56

28. 5. Diagnostic plate (22-25)
• 26, 42, 35 & 96
• Normal person able to read correctly
• Strong protenomaly & protenopia read only
6, 2, 5 & 6
• For mild protenomaly - 6, 2, 5 & 6 are clearer
than other
• Strong deuteranomaly & deutranopia read only
2, 4, 3 & 9
• For mild deuternomaly -2, 4, 3 & 9 are clearer
than other
Ishihara color vision chart
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Jennifer Birch Diagnosis of
defective color vision pg 56

29. Protan & deutran deficiency
Ishihara color vision chart
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30. 6. Tracing plate (26-38)
• It contains the pathways
• It is use in illiterate person & children
Ishihara color vision chart
9/28/2022
Jennifer Birch Diagnosis of
defective color vision pg 56

31. Analysis of result
• Normal – if the 17 or more plate are read correctly
• Color Vn defect – if the 13 or less than 13 plates
are read
• Repeat test – if between 13-17 plates are read
Ishihara color vision chart
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Jennifer Birch Diagnosis of
defective color vision pg 57

32. Method for ishihara color vision test
• Good room Illumination as day light.
• Patient should wear appropriate spectacle
correction & occlude one eye.
• The test plate is held at a distance of 75cm.
• Plane of the plate & line of the sight of vision
should be perpendicular ( tilted 45˚)
• Ask to patient to read the plates.
• For illiterate pt. ask to trace the line between
two X’s.
9/28/2022
Jennifer Birch Diagnosis of
defective color vision pg 57

33. American Optical Hardy Rand
Rittle Plate (AOHRR)
• Based on pseudoisochromatic test
• To determine red green and blue yellow color
vision defect
• Consist of 24 plates with vanishing design
containing geometrical shape
• 4 introducing plates ,6 screening plate,10 plates
for grading severity of protan &deutan, 4 plates
for grading severity of tritan defect
9/28/2022 Paul L. Pease- CR Borish’s,268

34. Holmgren Wool Test
• Based on color matching
• the aim is to determine isochromatism color
confusion by encouraging child to select wool
sample which appears similar in hue
• 3 test skeins yellow-green, pink & red
• Wools are placed on gray surface & person select
matching shades for each test skeins
• Viewing time of 1min
9/28/2022
Jennifer Birch Diagnosis of
defective color vision pg 52

35. 9/28/2022
Holmgren Wool Test

36. Farnsworth-Munsell 100 hue test
• It provides most sensitive assessment of hue
discrimination
• It is use for red-green & blue-yellow deficiency
• Four 20˝×1.75˝×1.25˝ trays, housed in a
21.5˝×6.12˝×2.5˝ carrying case
• Total of 85 numbered disks with varying hues
• Color reference size is 7/16˝ diameter
• Each disk is numbered to facilitate scoring
9/28/2022 Paul L. Pease- CR Borish’s,269

37. Farnsworth-Munsell 100 hue test
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Farnsworth Munsell 100 Hue
Scoring Software

38. Farnsworth D –15 test
• It is use for red-green & blue-yellow deficiency
• Capable of detecting moderate to severe color vision
deficiency
• Contains a 12 mm reference cap & 15 numbered
disks with all different hues
• Caps which substends an angle of 1.5 degree at 50
cm
• The patient’s task is to arrange the colored caps in
order compared to the reference cap
9/28/2022 Paul L. Pease- CR Borish’s,273

39. 9/28/2022

40. Anomaloscope
• Based on color match known as Rayleigh equation
R+G=Y
• it is use to determine red-green defect
• On the instrument monochromatic yellow light is
presented in half of a 2˚ circular field & a mixture of
monochromatic red-green light is presented in other
half
• Patient tasks is to match mix spectral red green lights
to other half the yellow light
9/28/2022
Jennifer Birch Diagnosis of
defective color vision pg 53
Paul L. Pease- CR Borish’s,275

41. Nagel’s Anamaloscopes
• 2 knobs : one changes the brightness of yellow &
other changes the mixture of red & green
• The matching range recorded from matching
limits obtained on red/green mixture scale
9/28/2022
Jennifer Birch Diagnosis of
defective color vision pg 53
Paul L. Pease- CR Borish’s,275

42. 9/28/2022
Nagel’s Anamaloscopes
Yellow
light
Mixture of
red & green
light

43. Lantern test
• Light used are either red,green or white
• Two light are presented at a time in any combination
• Call out immediately name of the color 1st top then
bottom
• Nine pairs of lights are presented
• Test is failed if the average error on last 2
administration is >1
9/28/2022 Paul L. Pease- CR Borish’s,280

44. Lantern test
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45. 9/28/2022
Lantern test
1st run
2nd run
3rd run
1
GR
3
GW
4
GG
5
RG
6
WR
7
WW
8
RW
9
RR
2
WG
# of error/
run
Score form for the Lantern Test

46. REFERENCE
• Paul L. Pease -Borish’s clinical refraction,
Chap. 9, Pg 243- 291
• Jennifer Birch – Diagnosis of defective color
vision , Pg 3-110
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47. 9/28/2022