nbeo 2 color vision Flashcards
color vision anomalies are defined as either ___ or __
color vision anomalies are defined as either congenital or acquired
congenital anomalies are usually
congenital anomalies are usually
- bilateral
- symmetrical
- red/green
- seen in males
- X-linked, inherited color anomalies from mother who are carriers
approximately _% of males are affected with color vision anomalies.
approximately 5% of males are affected with color vision anomalies.
acquired anomalies
- assymmetric
-associated w/ pathology
Anomaly: green weak
deficiency:
pigment:
Anomaly: green weak
deficiency: deutan
pigment: chlorolabe
Anomaly: red weak
deficiency:
pigment:
Anomaly: red weak
deficiency: protan
pigment: erythrolabe
Anomaly: blue/yellow confusion
deficiency:
pigment:
Anomaly: blue/yellow confusion
deficiency: tritan
pigment: cyanolabe
anomaly: no color perception
deficiency:
pigment:
anomaly: no color perception
deficiency: red monochromat
pigment: rhodopsin
Dichromats
dont have their respective photopigment
- have nope in the name
trichromats
-have all the photopigments but perception of color is shifted on the spectrum
how does reds appear to protanope vs deuteranope?
red will be very dim for protanope
will not be dim for deuteranopes
which photopigment belongs to which deficiency
deficiency: protan
anomaly: red weak
pigment: erythrolabe
- PROtagonist wears RED & saves EVERYONE
Person with _________ color deficiency benefits from wearing X-chrom CL.
dichromats
dichromats who wear X-chrom contact lenses. How does it work?
Red CL on eye will create color disparity between two eyes and shift color absorption curve and confusion lines toward normal color vision.
- will help pt distinguish between reds and greens
what is an alternative to wearing a x-chrom CL to create color disparity?
carry red filter to hold over the eye whenever you need to distinguish colors
achromatopsia/red monochromatism
-confirm with ERG: lack any cone response- poor or no color perception
-20/200 vision or worse
-photophobia
-eccentric viewing
-pendular nystagmus
-central scotoma
-normal looking fundus
Ishihara or HRR are used to pick up ___ color deficiencies
Ishihara or HRR are used to pick up red/green color deficiencies
- doesn’t distinguish deutan vs protan
-everyone should be able to distinguish 1st plate of Ishihara test
Farnsworth D-15 includes 15 color caps. Explain interpretation/why
Mean age: 39.3+/-10.9 years
Results places on graph for interpretation
-test distinguish bw deutan, protan, tritan defect
Nagel anomaloscope
ONLY color vision test to distinguish a dichromat vs anomalous trichromat
-view split field with yellow test field on bottom and red/green mixture field on top
-adjust brightness of yellow and red/green mixture
Goal: math the top and bottom
Nagel anomaloscope
color vision anomaly: normal
mixture field:
test field:
Nagel anomaloscope
color vision anomaly: normal
mixture field: 45
test field: 17
Nagel anomaloscope
color vision anomaly: protanope
mixture field:
test field:
Nagel anomaloscope
color vision anomaly: protanope
mixture field: 73 Red, test field (0)
test field: test field 0
** confusing?
Nagel anomaloscope
color vision anomaly: deuteranope
mixture field:
test field:
Nagel anomaloscope
color vision anomaly: deuteranope
mixture field: 0-73 look the same
test field:17
Nagel anomaloscope
color vision anomaly: protanomalous Trichromate
mixture field:
test field:
Nagel anomaloscope
color vision anomaly: protanomalous Trichromate
mixture field: >45 (more red)
test field: 10
Nagel anomaloscope
color vision anomaly: Deuteranomalous Trichromate
mixture field:
test field:
Nagel anomaloscope
color vision anomaly: Deuteranomalous Trichromate
mixture field: <45 ( more green)
test field: 17
