Arrangement Tests Flashcards
What are some advantages of arrangement tests?
Identify all types of defect
Can monitor acquired defects
Can assess severity of defects
What are some disadvantages of arrangement tests?
Not a screener
If limited dexterity, px may struggle
What distance should you do D15 at?
15cm
How many crossings on the D15 is considered a moderate defect?
2
How many crossings on the D15 is considered a severe defect?
More than 2
What categories are colours separated into in The Munsell System of Specifying Colour?
Wavelength (hue)
Value (brightness)
Chroma (saturation)
What Munsell System grades does the D15 use?
Hue: various
Value: 5
Chroma: 4
What differences does the desaturated D15 test have? What difference does this make?
Reduced value and chroma
Test is more difficult
Picks up milder defects
How is the specificity affected in the desaturated D15?
Reduced - more ‘normals’ can fail it
On the Farnsworth-Munsell 100 Hue Test, how much of a misplacement counts as an error?
Difference of 2 between neighbouring caps
On the results for a Farnsworth-Munsell test, what does the direction of the spokes indicate?
Type of defect
On the results for a Farnsworth-Munsell test, what does the numerical score of the errors indicate?
Larger score = higher severity
On the Farnsworth-Munsell, what are the mean positions for a protanope?
17 and 64
On the Farnsworth-Munsell, what are the mean positions for a deuteranope?
15 and 58
On the Farnsworth-Munsell, what are the mean positions for a tritanope?
5 and 45.5
Will the Farnsworth-Munsell pick up mild defects?
Yes
When is performance best on the Farnsworth-Munsell?
Late teens
What distance should the City Uni test be performed at?
35cm
How long should you present each page of the City Uni test for?
3 seconds
How does the City Uni test work?
Each colour around the central dot is either: normal, protan, deutan or tritan
Which deficiency makes the least mistakes on the City Uni test?
Protans
How does the Mollon-Reffin test work?
Works out limits of px’s ability to discriminate between hues using staircase method - starts at most desaturated and moves out on each line
Start with protan, then deutan, then tritan
Put each cap within grey caps and ask px to differentiate - if can, reduce saturation, if can’t increase
On the tritan line on Mollon-Reffin, what is an acceptable result for a px with possible lens yellowing?
T2
