ASSESSMENT OF BINOCULARITY IN
NONSTRABISMIC PATIENTS 2025 TO 2026
COMPLETE STUDY GUIDE CLINICAL
ASSESSMENT PRACTICE QUESTIONS AND
EXAM REVIEW
What is forced fixation disparity testing?
measuring fixation disparity while changing vergence demand
what prism increases exo fixation disparity?
increase BO
what prism increases eso fixation disparity?
increase BI
what is forced vergence fixation disparity testing especially useful for?
1. unclear etiology of symptoms
2. steep slope
3. large associated phoria
4. significant fixation disparity associated with symptoms
,What is the AC/A?
change in accommodative convergence that is associated with a given
amount of accommodative increase or relaxation
What are types of AC/A?
1. calculated
2. gradient
3. response
What is the expected AC/A value?
4/1 ± 2
What is the equation for calculated AC/A?
= IPD (cm) + ND (m) * (near - distance phoria)
What to consider when measuring AC/A?
1. effect of proximal accommodation
2. effect of lag of accommodation
, What type of AC/A measurement is best in determining if you should
prescribe an add or not?
gradient AC/A
What is the main difference between gradient and response AC/A?
gradient AC/A assume accurate accommodation
response AC/A measures both deviation and accommodative accuracy
what is testing fusion ranges?
assessment of positive and negative fusion ranges
How quick should you move the prism bar when doing bar vergences?
2pd/1sec
What must you ask at every single prism step during bar vergences?
single and clear
What distances is versions/ductions done at?
30cm
NONSTRABISMIC PATIENTS 2025 TO 2026
COMPLETE STUDY GUIDE CLINICAL
ASSESSMENT PRACTICE QUESTIONS AND
EXAM REVIEW
What is forced fixation disparity testing?
measuring fixation disparity while changing vergence demand
what prism increases exo fixation disparity?
increase BO
what prism increases eso fixation disparity?
increase BI
what is forced vergence fixation disparity testing especially useful for?
1. unclear etiology of symptoms
2. steep slope
3. large associated phoria
4. significant fixation disparity associated with symptoms
,What is the AC/A?
change in accommodative convergence that is associated with a given
amount of accommodative increase or relaxation
What are types of AC/A?
1. calculated
2. gradient
3. response
What is the expected AC/A value?
4/1 ± 2
What is the equation for calculated AC/A?
= IPD (cm) + ND (m) * (near - distance phoria)
What to consider when measuring AC/A?
1. effect of proximal accommodation
2. effect of lag of accommodation
, What type of AC/A measurement is best in determining if you should
prescribe an add or not?
gradient AC/A
What is the main difference between gradient and response AC/A?
gradient AC/A assume accurate accommodation
response AC/A measures both deviation and accommodative accuracy
what is testing fusion ranges?
assessment of positive and negative fusion ranges
How quick should you move the prism bar when doing bar vergences?
2pd/1sec
What must you ask at every single prism step during bar vergences?
single and clear
What distances is versions/ductions done at?
30cm
