Table 1.

Diagnosis criteria for classification of general binocular dysfunctions.

Convergence insufficiency

Symptoms are associated with reading or near tasks

Signs need to be present: signs 1–3 & 1 of 4–6

1 Moderate to high exophoria at near >6Δ

2 Reduced positive fusional vergence at near ≤12/15/4 for blur, break, & recovery (at least 1 of 3)

3 Receded near point of convergence ≥10 cm for break point

4 Low AC/A ratio <3/1

5 Fails binocular accommodative facility with +2.00 D, ≤2.5 cpm

6 Low NRA ≤1.50 D

Basic exophoria

Symptoms are associated with distance & near tasks

Signs need to be present: signs 1 –2 & 1 of 3–4

1 Exophoria of approximately equal magnitude at near & distance

2 Reduced positive fusional vergence at distance & near ≤12/15/4 for blur, break, & recovery (at least 1 of 3)

3 Normal AC/A ratio

4 Fails binocular accommodative facility with +2.00 D, ≤2.5 cpm

Convergence excess

Symptoms are associated with reading or other near tasks

Signs need to be present: signs 1 –2 & 1 of 3–4

1 Significant esophoria at near >2 Δ

2 Reduced negative fusional vergence at near ≤9/17/8 for blur, break, & recovery (at least 1 of 3)

3 High AC/A ratio, >7/1

4 Fails binocular accommodative facility with +2.00 D, ≤2.5 cpm

5 Low PRA ≤1.25D

AC/A = accommodative convergence/accommodation ratio; cpm = cycles per minute; NRA = negative relative accommodation; PRA = positive relative accommodation.