Subjective Refraction

Question 1

What is the order of subjective refraction

Answer 1

BVS
Duochrome
Cyl axis
Cyl power
+1.00 blur
Swap to other eye
Then binoc balance

Question 2

How to do BVS

Answer 2

Show plus lens and ask “is it better, worse or the same”
Show minus lens and ask “is it better or smaller and darker”

Question 3

How to do duochrome

Answer 3

Show red/green target and ask “are the numbers on the top clearer on the red or green”. If red then add minus lens and if green then add plus lens

Question 4

How to find axis for cyl

Answer 4

Match cross cyl handle with lens axis and ask if it’s rounder and cleaner with 1 or 2
(Use cluster of spots as target)

Question 5

How to find cyl power

Answer 5

Match markings on cross cyl to axis of lens and ask if it’s rounder and cleaner with 1 or 2
(Use cluster of spots as target)

Question 6

How do u do binocular balance

Answer 6

Block one eye with +1.00 and show the uncovered eye a +0.25 and ask if it’s better, worse or the same.
Then do the same for the other eye.

Question 7

How to do +1.00 blur

Answer 7

Show a +1.00 with opposing eye occluded and make sure px can see 6/12. If not then add more plus or fix during binoc balance

Question 8

How to check near ADD

Answer 8

According to px age add a near ADD and check NVA monocularly

Measure this distance

Question 9

How to check near range

Answer 9

Ask px to move near reading pad further back until it goes blurry. Measure this distance.
Then ask px to move close till it goes blurry and measure this distance.
Between these distances is the near range of the px