Color Vision Ch 8

A patient that sees the mixture as "too green" and adds more red will set a match _____ the normal range and will change the luminance. This describes ______.

above protanomaly

An individual who is TOTALLY color blind has _____. They have black & white vision. They are very ____ sensitive. Blues will appear ____.

achromatopsia light brighter

The affected photopigment's _____ _____ is shifted toward the other 'normal' photopigment.

action spectrum

People with 3 cone photopigments but 1 is different from normal are called ______ trichromats.

anomalous

A patient that sees the mixture as "too red" and adds more green will set a match _____ the normal range and will NOT change luminance. This describes ______.

below Deuteranomaly

They have NO wavelength discrimination from 450-500 nm ( ____ and ____ colors)

blue & green

Acquired Color Defects affect the eyes to different degrees and is often _____-_____. They have frequent color naming errors and _____ varies.

blue-yellow severity

Inherited Color Defects are ______ for the two eyes and almost always ____-____. They remain stable throughout life.

symmetrical red-green

Male with CVD, color normal female: all daughters are ____ and all sons are ____.

carriers NT

Rod monochromats do not have _____.

cones

Deuteranopes and protanopes have ______ lines between 540 nm and 700 nm on the spectral locus because S cones don't have sensitivity beyond 540 nm. They can match with ANY mixture of red-green on the anomaloscope because they're ______ beyond 540 nm.

confusion monochromats

Colors that cannot be discriminated by dichromats are found on _____ _____.

confusion lines

If your 3 photopigments are normal, you don't have a color vision deficiency. You are a normal _____.

trichromat NT

Dr. Bailey had a student who could not distinguish between white and a yellow highlighter. The student was most likely a ____. White and 570 look the same because it lands on a ____ point.

tritan neutral

A point where confusion lines converge is called ____ (_____) point

copunctal (convergence) point

When the SWS cone is anomalous it is called ______.

tritanomalous

The most common inherited color vision defects are inherited in an ___-____ ____ manner.

x-linked recessive

For protanopes & deuteranopes, saturation discrimination goes to ____ at the neutral points.

zero worst saturation discrimination

The prevalence of anomalous trichromatic of males is about ___% and ___% of females.

~6% of males ~0.4% of females (think 1/2 a percent)

Colors that lie outside the spectral locus are called _____ _____ and are not realizable.

imaginary primaries

Dichromats have NO color discrimination beyond 540 nm because they're only using ONE cone type (color discrimination = ___ )

infinity

The dueteranopia neutral point is a ____ wavelength

longer

Which color vision book is best for screening red-green deficiencies?

Ishihara

A protanope has the photopigment ___ missing. Prevalence of males: __%

LWS 1%

A deuteranope has the photopigment ____ missing. Prevalence of males: __%

MWS 1%

Using the anomaloscope, you can tell protanopes and deuteranopes apart by ______ _____.

luminosity differences

Which of these, rod monochromats or tritanopes, would show a significant change in luminosity functions compared to color normals? Why?

Rod monochromats since long wavelengths (red) look extremely dim. Tritanopes are only missing S cones. Photopic luminosity function is based on M and L cones.

What are the 3 types of cone populations?

S (blue) M (green) L (red)

A tritanope has the photopigment ____ missing. Prevalence: (T + TA is 1 in 30K)

SWS

Blue cone monochromats have rods and ____ cones

SWS

Beyond 540 nm, s-cones do NOT function, therefore, dichromats become _____.

monochromats.

Tests for acquired color defects must be done _____ since eyes are usually affected differently.

monocularly

Dichromats (P & D) have their best wavelength discrimination for spectral lights at their _____ point.

neutral

A point on spectral locus, on a confusion line going through white and the copunctal point is called the _____ point.

neutral point

For protanomalous & deuteranomalous patients, saturation discrimination comes close to zero but anomalous trichromatic do not have ____ ____.

neutral points

Inside the locus and on the purple line are where you would find _____ _____.

nonspectral colors

The L cone's action spectrum is shifted left towards M in those with _____.

protanomaly

When the LWS cone is anomalous it is called _____. Prevalence is __% of males.

protanomaly 1

When the luminosity of "red" field looks dim, the patient will alter the luminosity of the yellow. Both the top and the bottom will have very dim settings. This describes a ______ patient.

protanope

The photopic luminosity curve is shifted significally to the left for _____ because they have only M & S cones. Since ____ cones do NOT contribute to luminosity function they effectively only use ___ cones.

protanopes S M

MWS and LWS are coded for on the x-chromosome. Deuteranopia and protanopia are x-linked _____.

recessive

Protanopes would not be able to see a ____ laser pointer because it would appear very dim. They may also have slower reaction times while driving.

red

What does SWS/MWS/LWS stand for?

Short, medium, and long wavelength sensitive

In DA, the action spectrum is shifted ____ towards the ___ cone. This causes a loss of _____.

right L discrimination

Monochromats can be ____ or ____ cone monochromats and are color _____.

rod blue blind

When you know that white has changed after adding a spectral color. This describes _____ _____.

saturation discrimination

What color vision test utilizes this facet of wavelength discrimination?

The anomaloscope utilizes wavelengths from 540 to 700 along the confusion line for protanopes and deuteranopes

Given a quantitatively diagnostic plate made up of a grey background, a greenish symbol, and a blue-green symbol, what color defectives would the plate distinguish? Which type of color defective would see which symbol?

The deutan would miss the green circle and identify the blue triangle. The protan would miss the blue triangle and identify the green circle.

The anomaloscope results depend on the _____ of anomalous trichromacy. Very mild DAs or PAs would almost look like color normals.

severity Severe DAs or PAs would have a wide range of acceptable settings and almost look like a dichromat

The protanopia neutral point is a ____ wavelength.

shorter

An inverted U-shaped envelope of diagram of spectral colors/lights describes a _____ _____.

spectral locus

Would a deuteranope confuse a yellow hue with an orange?

YES

Would a tritanope confuse a saturated red with a violet?

YES

Color normals have best wavelength discrimination about ___ nm and have minima at ____ & ____ .

1 nm 490, 590 (green & orange)

The prevalence of dichromacy is __% of males and ___% of females.

2% of males 0.02% of females (super rare)

Rod monochromats have a prevalence of 1 in ____. There is no sexual predilection. It is found on chromosome ___ and is autosomal ____.

30K 2 recessive

A protanope's neutral point and best wavelength discrimination wavelength is at ____ nm.

495 nm

Female carrier, male NT: ____% of daughters are carriers and ____% of sons have CVD.

50% 50%

A deuteranope's neutral point and best wavelength discrimination wavelength is at ____ nm.

500 nm

Tritanopes have two minima, one at ____ nm and also very low wavelengths.

570

Color normals have their worst saturation discrimination at ____ (____) which looks the most desaturated.

570, yellow

SWS is coded for on chromosome ___ and is autosomal _____.

7 dominant

The highest prevalence ( __%) of color deficiency is found in Caucasians. It is lower everywhere else besides the US & UK.

8%

The ONLY way to differentiate between a trichromat and a dichromat is using an ______.

Anomaloscope

What are the two types of color "deficiencies"?

Anomalous trichromacy Dichromacy

What general colors would a dichromat confuse?

Dichromats will confuse colors along their respective confusion lines

True or False? Dichromacy is more rare than monochromacy.

FALSE. Monochromacy is very rare.

Of the color vision book tests, which has the best diagnostic performance?

HRR

Which color vision book is best for screening blue-yellow deficiencies?

HRR

True or False? A majority of those color deficient are anomalous trichromats.

True

True or False? Patients with congenital x-linked color deficiency rarely misname color.

True

What is wavelength discrimination like beyond 540 nm for a color normal?

Not as good since S cones do not have sensitivity across entire visible spectrum. They are essentially dichromats past this wavelength.

If a patient is found to have a matching range of 50 to 73 on the anomalscope, with a lower luminance setting for the red-green mixture setting 73... what kind of deficiency do they have?

Protanomaly

What is wavelength discrimination like beyond 540 for a red-green defective?

They have no wavelength discrimination because only one cone type is functioning. They are essentially monochromats

The most common anomalous trichromat is _____ where the MWS cone is different. Prevalence __% of males.

deuteranomaly 5%

If the luminosity stays constant for both the test and reference fields the patient is a ______. The top will be pure red and the bottom will be a solid yellow.

deuteranope

The photopic luminosity curve is shifted very slightly to the left for _____. However, they have essentially the same V lambda curve as color normal and no luminosity consequences.

deuteranopes

A _____ can match colors using only 2 primary colors.

dichromat

People with only 2 cone photopigments are called _____.

dichromats

The luminous efficiency of long wavelengths for protanopes is quite bad and long wavelengths like red appear very ____.

dim