Color Vision Testing (M1) Flashcards
What do blue-cone monochromats present with?
- almost no color vision
- very poor va
- nystagmus
- phtophobia
For protanomalous trichromats what kind of light are the more sensitive to? 1. Less sensitive? 2. What color do they need more of to match a normal yellow match? 3. Is the luminance efficiency function up or down in the long wavelength portion (is the yellow match to a red light brighter or dimmer)? 4
- green light
- red light
- red
- down (dim)
For deuteranomalous trichromats what kind of light are the more sensitive to? 1. Less sensitive? 2. What color do they need more of to match a normal yellow match? 3. Is the luminance efficiency function up or down in the long wavelength portion (is the yellow match to a red light brighter or dimmer)? 4
- red light
- green light
- green
- down (dim)
What are the differences between the M and L peak sensitivities for each classification of anomalous trichromats: 1=severe, 2=moderate, 3=mild, 4=normal
- 3nm
- 6nm
- 12nm
- 30nm
What are the reasons to test for color vision?
- diagnose hereditary color anomalies
- assess requirements for certain occupations
- assist in diagnosis and monitoring of ocular diseases
What are the types of plates that are commonly used for color vision screening to discriminate between CV normal and abnormal?
pseudoisochromatic plates
What defects are Ishihara plates able to detect?
R/G only
What defects are HRR plates able to detect? 1. What shapes are used? 2
- R/G and B/Y
2. circle, X and triangle
What points along the CIE diagram do the HRR plates present a stimuli?
- between copunctal point and white point
2. between white point and neutral point
What points along the CIE diagram do the Ishihara plates present a stimuli? 1. How do they diagnose the type of dichromacy? 2
- on other confusion lines through the copunctal point (so if on confusion line then can’t see the number)
- copunctal points differ
What is the standard amount of pseudoisochromatic plates? 1. How many misses are allowed to occur to pass? 2. How many missed to fail? 3
- 38
- 4 or fewer
- 7 or more
What are the disadvantages of pseudoisochromatic plates?
- many R/G only
- cannot reliably grade severity or defect
- can’t tell how good color discrimination is
- cannot 100% discriminate Protans from Deutans (but does well)
What is the color arrangement test that has 16 colors that must be ordered correctly? 1. How many defectives pass? 2. Does this test R/G or B/Y? 3.
- Farnsworth Panel D-15 (and desaturated)
- 50% (normal) and 25% (desaturated)
- both
For the Farnsworth Panel D-15 what constitutes a major error? 1. How many major errors constitutes failure? 2
- skip numbers by more than 2
2. two or more
What does the D-15 fail to discriminate between?
extreme anomalous trichromats and dichromats
