Color Vision Deficiencies - Monochromats & Protanopia Flashcards
Describe Rod Monochromacy
Congenital?, Rods/Cones functional?, What colors do they see?, Genetic Inheritance type?) (AR, X-linked, AD, etc.
- Congenital
- Rods functional, cones defective
- Sees grey, can distinguish some color
- AR inheritance
Describe Blue Cone Monochromacy
(Congenital?, Rods/Cones functional?, What colors do they see?, Normal night vision? Genetic Inheritance type?) (AR, X-linked, AD, etc.)
- Congenital
- Rods functional, short wavelength cones function
- Only sees blue
- Normal night vision
- X-linked inheritance
What ocular signs are NOT seen with Rod Monochromacy or Blue Cone Monochromat?
A. Decreased VA B. Photophobia C. Nystagmus D. Unremarkable Fundus E. Normal Luminance Function
E. Normal Luminance Function
Luminance function is abnormal
Monochromats are unable to make wavelength based discriminations? TRUE/FALSE
TRUE
Which is TRUE about dichromats?
A. Can not make wavelength based color discriminations
B. Will have the same amount of metameric matches as those without color deficiency
C. Have a W shaped curve with one area best for color discrimination
D. Protanopes will appear less saturated at 492 nm and Deutanopes appear less saturated at 498 nm
E. Protanope and Deutanopes have the same white point in a CIE Chromaticity Diagram
D. Protanopes will appear less saturated at 492 nm and Deutanopes appear less saturated at 498 nm
- Can make some wavelength discriminations
- Has more metameric matches
- U shaped curve
- Protanopes, Deuternopes have different white points on CIE Chromaticity
Describe Protanopia
(What cone is missing, what region (color and wavelength) will not be seen/monochromatic, shortest visual spectrum?, what colors are confused, Inheritance and prevalence)
- erythrolabe, long wavelength cone missing
- red is not seen, monochromatic above 545 nm
- Confuse red, yellow, green, blue and purple
- X-linked recessive, 1% males
Protonopes are essentially monochromatic beginning at what wavelength?
A. 492 nm B. 495 nm B. 540 nm C. 545 nm D. 555 nm
C. 545 nm
Unable to detect Red from 545-700 nm
Protonopes have best wavelength descrimination at what wavelength?
A. 492 nm B. 495 nm B. 540 nm C. 545 nm D. 555 nm
B. 495 nm
Both S, M cones are responsive at this wavelength.
Color normal is at 490 and 580 nm
Protonopes have peak luminosity at what wavelength?
A. 492 nm B. 495 nm B. 540 nm C. 545 nm D. 555 nm
B. 540 nm
Color Normal is 555 nm, peak luminosity will be shifted slightly towards shorter wavelengths
Protonopes have saturation at what wavelength?
A. 492 nm B. 495 nm B. 540 nm C. 545 nm D. 555 nm
A. 492 nm
Normal Trichromat is at 570 nm, significant shift to the left
Clinically what are two significant cautions with Protanopes (Relates to driving)
- brake lights and stop lights
