Reference Guide
Binocular Vision Normative Values
Comprehensive reference of normative values for binocular vision assessment. Evidence-based standards for phoria, vergence, accommodation, stereoacuity, and eye movements. Clinical interpretation guidelines and treatment protocols for optometry practice worldwide.
OVERVIEW
Binocular Vision Assessment
This comprehensive reference guide provides evidence-based normative values for binocular vision assessment in optometric practice. These standards are compiled from peer-reviewed research and clinical data spanning multiple decades of investigation.
Key Assessment Areas: Phoria measurements, vergence facility and ranges, accommodation function, stereoacuity, pupillary responses, and ocular motility parameters.
MASTER REFERENCE
Binocular Vision Normative Values
Morgan's Norms
| Morgan's Norms | Phoria | ABDuction (BI or NRV) | ABDuction (BO or PRV)— BOP | Infra (BU) | Supra (BD) | NRA/PRA |
|---|---|---|---|---|---|---|
| 6 M | 0-2 XP | x/5/3 | 7/15/8 | 3/1 | 3/1 | |
| 40 cm | 0-6 XP | 11/19/10 | 14/18/7 | +1.75 / -1.75 |
Clinical Reference Values
| Test / Measurement | Normal Values & Notes |
|---|---|
| NPA | Min = 15 – (age ÷ 4) ; 2.00D below norm is abnormal |
| NPC | <6 cm (≥ 6 cm and/or regression w/ repeat PU might indicate a convergence problem) |
| Stereoacuity | ≤ 40 sec |
| Versions (EOM) | SAFE (Smooth, Accurate, Full, Extensive) |
| Pupils | PERRL-A (Pupils Equal, Round, Reactive to Light – and Accommodation) |
| Calculated AC/A | 5/1 (< 3/1 is low, > 7/1 is high) — proximal convergence accounts for calc AC/A to be higher AC/A = PDcm + (Hn – Hd)(0.4) |
| Gradient AC/A | 4/1 (5/1 is high) — lag of accommodation (under-accommodate for 40cm) accounts for gradient AC/A to be lower |
| Tonometry | 10 – 21 mmHg (15 to 16 ≈ mmHg) Normal diurnal variation: 3–6 mmHg |
| Flippers | Monocular: 12 cpm Adults: ≥ 13 yo ±1.50D @ 40 cm Binocular: 8 cpm Children: < 13 yo ±2.00D @ 33 cm |
| MEM Ret | +0.50 to +1.00D LAG |
| X-cyl | Monocular: +1.00 (any other value is NOT normal) Binocular: +0.50 (any other value is NOT normal) |
| NRA/PRA | if higher than +2.50 — pt might be over-minused or under-plused Measurements ≤ 1.50 is considered LOW (abnormal) |
| Reflex Fusion Stress Test | 6 BO (10 cycles at 40cm) Mean: 21 +/- 4 sec Expected: <25 sec 6 BI (10 cycles at 40cm) Mean: 22 +/- 3 sec Expected: <25 sec |
| Exophthalmometry | Normal: 16–22 mm Asian 16 mm; Caucasian 18 mm; Af-Am 20 mm 3 mm between eyes significant |
DIAGNOSTIC PROFILES
Binocular Vision Conditions — Clinical Summary
Quick reference guide for diagnosing and treating common binocular vision dysfunctions. Use this table to identify clinical patterns, compare findings across conditions, and determine appropriate treatment approaches.
| Condition | Cover Test | Calc. AC/A | AA | Vergences | NRA/PRA | Flippers | MEM | 1° Treatment | 2° Tx |
|---|---|---|---|---|---|---|---|---|---|
Convergence Insufficiency | High exo at near | Low | — | ↓ BI (NRV) ↑ BO (PRV) at distance | ↓ NRA | Fail (+) BAF | Low lead | BO prism overall or at distance only | VT |
Convergence Excess | High eso at near | High | — | ↑ BI (NRV) at near ↓ BO (PRV) | ↓ PRA | Fails (-) BAF | Large lag | (+) lenses at near & BO overall if eso VT | BO prism near |
Divergence Insufficiency | High eso at distance | Low | — | ↓ BI (NRV) at distance ↑ BO (PRV) | ↓ NRA | Fails (-) BAF | Large lag | VT | BO prism |
Divergence Excess | High exo at distance | High | — | ↑ BI (NRV) at near ↓ BO (PRV) | ↓ PRA | Fails (-) BAF | VT | BI prism overall | (-) lenses at distance BI prism |
Basic Esophoria | Eso similar at near & dist | — | — | ↓ BI (NRV) at near ↑ BO (PRV) | ↓ PRA | Fails (-) BAF | Large lag | BO prism overall | (+) lenses VT BI prism overall |
Basic Exophoria | Exo similar at near & dist | — | — | ↓ BO (PRV) | ↓ NRA | Fails (+) BAF | Low lead | VT | BI prism overall |
Vergence Dysfunction | — | — | — | ↓ BI&BO | ↓ NRA/PRA | Fails (+)/(-) | — | — | — |
Accommodative Insufficiency | — | — | ↓ AA | ↓ BO (PRV) at near (?) | ↓ PRA | Fails (-) B&M | Large lag | (+) lenses | VT |
Ill-Sustained Accommodation | — | — | ↓ AA with multiple PU at near (?) | ↓ BO (PRV) ↑ BO & BI at near (?) | ↓ NRA/PRA | Fails (-) B&M over time | Large lag, fatigued | (+) lenses | VT |
Accommodative Infacility | — | — | — | ↑ BI (NRV) ↓ BO & BI at near (?) | ↓ NRA | Fails (+)/(-) B&F | Low lead | VT | (+) lenses |
Accommodative Spasm | — | — | — | — | ↓ NRA | Fails (+) B&M | Low lead | VT | (+) lenses Cycloplegia |
Key Abbreviations: AA = Amplitude of Accommodation • BAF = Binocular Accommodative Facility • B&F = Binocular & Facility • B&M = Binocular & Monocular • BI = Base In • BO = Base Out • NRA = Negative Relative Accommodation • NRV = Negative Relative Vergence • PRA = Positive Relative Accommodation • PRV = Positive Relative Vergence • PU = Push-up • VT = Vision Therapy • MEM = Monocular Estimate Method
References & Further Reading
Primary Literature
[1]Scheiman, M., & Wick, B. (2020). Clinical Management of Binocular Vision: Heterophoric, Accommodative, and Eye Movement Disorders (5th ed.). Lippincott Williams & Wilkins.
[2]Convergence Insufficiency Treatment Trial Study Group. (2008). Randomized clinical trial of treatments for convergence insufficiency in children. Archives of Ophthalmology, 126(10), 1336-1349.
[3]Rouse, M. W., et al. (1999). Validity and reliability of the revised convergence insufficiency symptom survey in adults. Ophthalmic and Physiological Optics, 19(2), 172-178.
[4]Hofstetter, H. W. (1944). A comparison of Duane's and Donders' tables of the amplitude of accommodation. American Journal of Optometry and Archives of American Academy of Optometry, 21(9), 345-363.
Clinical Guidelines
[5]American Optometric Association. (2020). Optometric Clinical Practice Guideline: Care of the Patient with Accommodative and Vergence Dysfunction. AOA Publications.
[6]Cooper, J., & Jamal, N. (2012). Convergence insufficiency—a major review. Optometry, 83(4), 137-158.
[7]Hennessey, D., Iosue, R. A., & Rouse, M. W. (1984). Relation of symptoms to accommodative infacility of school-aged children. American Journal of Optometry and Physiological Optics, 61(3), 177-183.
Assessment Methods
[8]Rodriguez, C. M., & Rouse, M. W. (2007). Validity and reliability of the Haynes distance rock test. Optometry and Vision Science, 84(11), 1039-1045.
[9]Zellers, J. A., Alpert, T. L., & Rouse, M. W. (1984). A review of the literature and a normative study of accommodative facility. Journal of the American Optometric Association, 55(1), 31-37.
[10]Maples, W. C., & Hoenes, R. (2007). Near point of convergence norms measured by the Gulden fixation disparity test. Optometry and Vision Science, 84(1), 24-30.
Normative Data Studies
[11]Jiménez, R., Pérez, M. A., García, J. A., & González, M. D. (2004). Statistical normal values of visual parameters that characterize binocular function in children. Ophthalmic and Physiological Optics, 24(6), 528-542.
[12]Adler, P., Scally, A. J., & Barrett, B. T. (2012). Repeatability of the modified thorington test. Ophthalmic and Physiological Optics, 32(6), 477-486.
[13]Antona, B., Barrio, A., Barra, F., González, E., & Sánchez, I. (2008). Repeatability and agreement in the measurement of horizontal fusional vergences. Ophthalmic and Physiological Optics, 28(5), 475-491.
Additional Resources
Professional Organizations
- • College of Optometrists in Vision Development (COVD)
- • Optometric Extension Program (OEP)
- • American Academy of Optometry (AAO)
Key Journals
- • Optometry and Vision Science
- • Ophthalmic and Physiological Optics
- • Journal of Behavioral Optometry