Colour vision

Question 1

Ishihara

Answer 1

Congenital RG defects
Doesn’t test tritonopia
75cm
Present each plate 3s

Question 2

Transformation plate

Answer 2

Correct = normal cv

Diff number = RG defect

Question 3

Vanishing plate

Answer 3

Seen = normal

Not seen - RG defect

Question 4

Hidden digit

Answer 4

See number - RG defect

See nothing =normal

Question 5

Classification plate

Answer 5

Only used if screening identifies RG defect/ 3+ plates wrong
See rhs number = protan
See Lhs number = deutan
Severe defect see none

Question 6

Tracing plate

Answer 6

Illiterate/language barrier pxs

Question 7

City colour vision

Answer 7

Derived d15
Good for acquired
Not as sensitive to mild RG defects as Ishihara
Not a screening test

Question 8

Farnsworth d15

Answer 8

15 small isochromatic discs - diff hue

Detect mod-severe defect

Question 9

F-munsell 100 hue

Answer 9

More sensitive than d15
Requires more time/conc
Not suitable for children

Question 10

What test would you choose for congenital/acquired and why

Answer 10

Congenital - BES - Ishihara

Acquired - monocular - city/d15

Question 11

Counselling

Answer 11

Explain genetics for congenital - no cure
Advise school/carers
Careers - army/RAF/pilot/electrical engineer/police/fire service/navy/lifeboat

Question 12

Genetics - congenital cv

Answer 12

X-linked