Binocular Vision Reference Guide

Binocular Vision Testing

Delve into the essential normative values that underpin effective binocular vision testing, a fundamental component of optometric assessments and patient care. This detailed guide offers optometrists a thorough overview of expected benchmarks for pivotal diagnostic tests including the Near Cover Test, NPC (Near Point of Convergence), Vergence Facility, Positive and Negative Fusional Vergence, and Amplitude of Accommodation. Accurate normative data is crucial for recognizing and diagnosing binocular vision anomalies, enabling clinicians to devise precise, tailored treatment plans.

Expected Values in Binocular Vision

Test	Expected Values
Near Cover Test	Ortho - 6XP
NPC	5/7cm Near \| 7/10cm Distance
Vergence Facility (3BI/12BO)	15 cycles/min
Positive Fusional Vergence	17/21/11
Negative Fusional Vergence	13/21/13
Positive Fusional Reserve (Blur/Break/Recovery)	7-11 / 15-23 / 8-12 △
Negative Fusional Reserve (Blur/Break/Recovery)	x / 5-9 / 3-5 △
Amplitude of Accommodation	Minimum: 15 - (¼)Age
Lag of Accommodation	+0.25 to +0.75
Positive Relative Accommodation	-2.37 (±1.00)
Negative Relative Accommodation	+2.00 (±0.50)
ACA	4/1 △

Binocular Vision Conditions

Condition	Cover Test	NPC	Vergence Facility	Vergence Amplitude	Binocular Acc. Facility	Monocular Acc. Facility	NRA/PRA	MEM	Accommodative Amplitude
Basic Exophoria	Exo, D=N	Normal	Low BO @ D&N	Low BO @ D&N	Fails (+)	Normal	Low NRA	Low	Normal
Basic Esophoria	Eso, D=N	Normal	Low BI @ D&N	Low BI @ D&N	Fails (-)	Normal	Low PRA	High	Normal
Accommodative Insufficiency	No Pattern	Normal	Normal	Normal	Fails (-)	Fails (-)	Low PRA	High	Low
Divergence Insufficiency	Eso, >D	Normal	Low BI @ D	Normal	Normal	Normal	Normal	Normal	Normal
Convergence Insufficiency	Exo, >N	Receded	Low BO	Low BO	Fails (+)	Normal	Low NRA	Low	Normal
Convergence Excess	Eso, >N	Normal	Low BI	Normal	Fails (-)	Normal	Low PRA	High	Normal
Fusional Vergence Dysfunction	Low Eso or Exo	Normal	Low BI & BO	Normal	Fails (+) & (-)	Normal	Low NRA/PRA	Normal	Normal
Divergence Excess	Exo, >D	Normal	Low BO @ D	Low BO @ D	Normal	Normal	Normal	Normal	Normal