with Complete Solutions
__ _____ contain a specific photopigment that detects long (____) wavelengths - ANS-L
cones; red
__ ______ contain a specific photo pigment that detects medium (______) wavelengths
- ANS-M cones; green
__ ______ contain a specific photopigment that detects short (______) wavelengths -
ANS-S cones; blue
_________ color vision anomalies are most prevalent - ANS-Inherited
_______________ provide a definitive diagnosis and quantification of color vision
status. It can differentiate _________ from _________ _________. - ANS-
Anomaloscopes; dichromacy; anomalous trichromacy
(1) "Scope" that patient looks into with a circle in it composed of 2 different colors
(2) One half is yellow and there is a knob that controls the brightness
(3) One half is a mixture of red and green and there is a knob that controls the
proportion of the mixture
(4) Patient turns the dials to "match" both halves of the circle - ANS-Anomaloscope
(1) all 3 types of cones are dysfunctional
(2) rods are functional
(3) poor VA (about 20/200)
(4) aversion to bright light
(5) central scotoma (blind spot)
(6) nystagmus (eyes move back and forth irregularly - ANS-Rod monochromat
(1) blue/yellow defect
(2) functional s-cone photopigment that is abnormal in sensitivity
(3) "blue weak"
(4) anomalous trichromat - ANS-Tritanomaly
(1) blue/yellow defect
(2) lacks the S-cone pigment
(3) "blue blind"
(4) dichromatic - ANS-Tritanopia
(1) Computer program that uses pseudoisochromatic plates
(2) Offers the potential to screen large numbers of people for color vision deficiencies
(3) Cannot distinguish between dichromatic and anomalous trichromatic color vision
, (4) A limitation of these tests is that the chromaticities of the plates may vary from
computer to computer due to variations in hardware and software settings - ANS-
Computer-Based Color Vision Tests (ex. The Waggoner Computerized Color Vision
Test)
(1) Good for screening
(2) Useful for identifying a defect or monitoring disease progression
(3) Useful for differentiating protanopia and deutan anomalies
(4) Cannot distinguish between dichromatic and anomalous trichromatic vision defects -
ANS-Pseudoisochromatic Plate (PIP) Tests
(1) have only a single type of functional cone, lack the pigment for the other 2
(2) typically normal VA (20/20) - ANS-Cone monochromat
(1) red/green defect
(2) functional l-cone photopigment that is abnormal in sensitivity
(3) "red weak"
(4) anomalous trichromat - ANS-Protananomaly
(1) red/green defect
(2) functional m-cone photopigment that is abnormal in sensitivity
(3) "green weak"
(4) anomalous trichromat - ANS-Deuteranomaly
(1) red/green defect
(2) lacks the L-cone photopigment
(3) "red blind"
(4) dichromatic - ANS-Protanopia
(1) red/green defect
(2) lacks the M-cone photopigment
(3) "green blind"
(4) dichromatic - ANS-Deuteranopia
(1) Require observer to place colored samples in sequential order on the basis of hue,
saturation, or lightness (or to sort samples based on similarity)
(2) Order is recorded as sequence of numbers printed beneath each cap
(3) Results plotted on score forms for analysis and interpretation
(4) Quantitative scores can be computed - ANS-Arrangement Tests (ex. Farnsworth
Dichotomous Test (Farnsworth D-15)
(1) tend to confuse blues and yellows
(2) transmitted in an autosomal dominant fashion - ANS-Blue/yellow hereditary defects
(1) tend to confuse reds and greens
(2) transmitted in an x-linked recessive fashion