Accommodation

Question 0

.Det lens req to neutralize reflex w/ MEM ret OR lag/lead if scope at neutrality distance w/ Nott ret

Answer 0

Target (in D = 100/distance in cm) - Neutrality (in D) = Lag if +, Lead if -

Question 1

.Motion seen with MEM ret

Answer 1

WITH -> Lag of acc
NEUTRAL -> Proper acc
AGAINST -> No acc

Question 2

.Interpretation of binocular flipper test results

Answer 2

Trouble clearing plus -> Overacc
Trouble clearing minus -> Acc infacility*

*maybe uncorrected myope avoid acc to keep minus to see clearly

Question 3

.Change Rx -> Change acc amp

Answer 3

Add + -> Increase acc amp (able to acc closer)

Question 4

.NRA vs. PRA - Def

Answer 4

(w/ + lens) NRA - Measure ability to relax acc

(w/ - lens) PRA - Measure ability to engage acc

Question 5

.Distinguish btwn exo due to acc insufficiency and true exo

Answer 5

w/ acc response testing (MEM or Nott ret)

LAG if acc insufficiency - Underacc
LEAD if true exo -Compensate by Overacc (more eso)

Question 6

.Use of binocular vs. monocular flipper test

Answer 6

Binoc - Maybe BV problem - Not enough compensating fusional verg

Monoc - Acc problem

Question 7

.Monoc flipper test procedures for adult

Answer 7

\+/- 1.50 
40cm
1 above T
20 cycles (1 cycle = 2 flips) 
Test for 1 min

Max time for normal = 90 sec

Question 8

.Reasons for reduced PRA

Answer 8

1) Insufficient acc

2) Insufficient NFV to compensate for convergence to keep target single

Question 9

.NRA/PRA procedure

Answer 9

“Tell me when the letters just start to become blurry” 1) Add plus (+0.25 DS at a time) OU, to relax acc so acc convergence is decreased and replaced w/ fusional convergence, allowing 1-2 sec after each lens change for patient to clear plus, 2) Record NRA - amount of ADDITIONAL plus (Rx + recorded result = lens used) that caused slight sustained blur, 3) Return to starting power, 4) Add minus (-0.25 DS at a time) OU, allowing time for patient to clear minus BUT if non-presbyope, stop adding lenses at -3.00 DS (record as > - 3.00), unless plotting the zone of clear single BV - then keep going, 5) Record PRA - amount of ADDITIONAL minus (Rx + recorded result = lens used) that caused slight sustained blur, IF cover one eye when blur is reported - if letters are still blurry (indicates acc = limited factor, not by fusional vergence ability), Final recording: e.g. NRA/PRA @ 40cm, +2.25 / -1.75 for patient w/ distance Rx of -2.00DS, sustained blur when looking through +0.25 DS and -3.75 DS, For presbyope w/ add, Use Rx + add as starting power

Question 10

.NRA/PRA norms

Answer 10

For non-presbyopes, Minimum: +1.75, -1.75