5/6 - Refraction, VF, Color, Contrast

Question 1

Initial sphere

-JND calculation

Answer 1

JND = snellen denominator/100

-typically based on entering DVA

Question 2

Can be used to determine legal blindness (mean deviation > 22dB)

Answer 2

Automated VF

Question 3

Arc perimetry

-what to do if suspect malingering

Answer 3

Occasionally turn the wand around during testing so that the target disappears. If they still claim to see it while turned, malingering confirmed

Question 4

Arc perimetry

-norms

Answer 4

Temporal = 90
Inferior = 70
Nasal = 60
Superior = 55

Question 5

Perimetry

-define preferred retinal locus

Answer 5

Retinal area that behaves as a pseudofovea, is adapted by the pt to see chosen object

Question 6

Color

• D-15 aka
• generally performed uni or binocularly

Answer 6

Panel 16

Binocularly

Question 7

MARS contrast sensitivity

• each letter fades by __ units
• have pt read until

Answer 7

0.04 log units

2 consecutive incorrect