color vision

Question 1

color vision

Answer 1

ability to discriminate between different wavelengths of light

Question 2

S-cone

Answer 2

blue

Question 3

L-cone

Answer 3

red

Question 4

M-cone

Answer 4

green

Question 5

visible spectrum

Answer 5

400nm (UV)-700nm (red)

Question 6

color

Answer 6

perception of electromagnetic radiation of a specific wavelength

Question 7

color can be specified by

Answer 7

its dominant wavelength and purity

Question 8

can light be added together from two or more sources?

Answer 8

yes

Question 9

2 basic types of color vision defects

Answer 9

1. inherited

2. acquired

Question 10

inherited color defect

Answer 10

• caused by an inherited genetic defect,
• present at birth (congenital), and remain constant throughout life
• absence of photoreceptor pigment
• both eyes
• red-green
• more males
• incurable

Question 11

acquired color defect

Answer 11

• caused by accompanying
• diseases/trauma/toxicity. may be present at any time, and may change over time
• may differ between eyes
• usually changes over time
• blue yellow
• males and females equally
• sometimes treatable

Question 12

Percentage of color deficient males

Answer 12

8%

Question 13

percentage of color deficient females

Answer 13

0.5%

Question 14

rods

Answer 14

does not preferentially detect light of certain wavelengths, but have a specific photopigment that detects light better in dim conditions

Question 15

How many types of light sensing cells in the retina?

Answer 15

4

Question 16

normal trichromats

Answer 16

normally functioning cones of all 3 types

Question 17

anomalous trichromats

Answer 17

functional cones of all three types, but one type is sensitive to a different wavelength of light than in normal trichromats

Question 18

dichromats

Answer 18

have only 2 types of functioning photopigments

Question 19

monochromats

Answer 19

have only one single type of photopigment

-such that only rods or a single type of cone function normally

Question 20

protanopia

Answer 20

dichromats that lack L-cone photopigment (red blind)

Question 21

protanomalous

Answer 21

analmous trichromatic with functioning L-cone photopigment that is abnormal in sensitivity to red (red weak)

Question 22

deuteranopia

Answer 22

lack of M cone photopigment (green)

Question 23

deuteranomalous

Answer 23

functioning M-cone photopigment that is abnormal in sensitivity to green

Question 24

tritanopia

Answer 24

lacking S cone photopigment

Question 25

tritanomalous

Answer 25

functioning S-cone photopigment that is abnormal in sensitivity to blue

Question 26

deutan

Answer 26

red-green

Question 27

tritan

Answer 27

blue-yellow

Question 28

monochromats

Answer 28

complete achromats - have no ability to distinguish chromaticity - entire visible spectrum seen as differing shades of gray

Question 29

typical rod monochromats

Answer 29

- have only one functional rods (all three types of cones are dysfunctional) - poor VA - aversion to bright light - central scotoma; often exhibit nystagmus as pre-teens

Question 30

atypical cone monochromats

Answer 30

have only a single type of functional cone pigment; usually with normal VA

Question 31

X-linked inheritance

Answer 31

L and M cone photopigment genes

Question 32

Autosomal inheritance

Answer 32

rod and S cone photopigment genes

Question 33

red-green defects

Answer 33

- most commonly encountered from inherited color defect | - X linked recessive, therefore much more common in males

Question 34

Blue-yellow defects and Achromatopsia

Answer 34

very rare, but do exist

Question 35

appropriate counseling

Answer 35

- parents - type and severity - haw it affects school, etc - how relates to occupation

Question 36

specific colored lenses

Answer 36

- do not restore normal color perception, but may aid color discrimination - may help with aversion to light and poor VA of rod monochromats

Question 37

acquired: causes by accompanying condition or toxicity

Answer 37

likely to be associated signs/symptoms that point to diagnosis

Question 38

defect may differ between eyes and usually changes over time

Answer 38

a defect that is more severe in one eye or that appears to change over time is likely to be acquired

Question 39

blue-yellow defect

Answer 39

acquired

Question 40

affects males and females equally

Answer 40

acquired

Question 41

chromatopsia

Answer 41

abnormal condition in which toxicity causes objects to be seen in a particular color or appear tinged with that color.

Question 42

managing acquired CVD

Answer 42

- directed toward treatment of primary cause - Dx primary cause involves other forms of testing and or consultation with other health care providers - repeat color testing frequently

Question 43

color vision testing

Answer 43

- lighting/viewing time/test distance - wear corrective eyewear (no tint) - usually one eye at a time - done before using dx drugs, instruments with bright lights - dont touch pages, store in dark

Question 44

pseudochromatic (PIC) plate tests

Answer 44

- most common - quick and easy - used to efficiently screen for inherited red-green defects

Question 45

arrangment tests

Answer 45

- useful for inherited and acquired defects - specify type of defect and quantify severity - sequence on hue, stauration

Question 46

anomaloscopes

Answer 46

- most accurate for diagnosis, but usually only found in specialty clinics (costly) - metameric matches

Question 47

PIC plate tests-transformational plates

Answer 47

person with color defect reads one figure and those with normal color vision another

Question 48

PIC plate tests-vanishing plates

Answer 48

person with color defect cannot read figure easily read by those with normal color vision

Question 49

PIC test plats-hidden digit plates

Answer 49

person with normal color vision fails to read a figure those with a color defect are able to read

Question 50

PIC test plates-diagnostic plates

Answer 50

figure is readable by those with one type of color vision defect, but not another

Question 51

occupational tests of color vision

Answer 51

PIC tests | arrangment tests

Question 52

color vision requirements

Answer 52

-drivers license - very few require color test. -aircraft pilot- can be color blind, but depends on severity and what colors you can/can't recognize military- won't be eligible for some MOS