Table 9.

Convergence Insufficiency and Reading Study (CIRS) group's criteria for convergence insufficiency.

Anomaly types and clinical signs
Convergence insufficiency clinical signs
(1) Exophoria at near.
(2) Exophoria at near ≥4 prism diopter (pd) greater than far.
(3) Insufficient fusional vergence defined as either (i) fails Sheard's criterion or (ii) poor PFV at near ≤12 pd Base out (BO) to blur or ≤15 pd BO break. Poor BO break was used for insufficient PFV criteria.
(4) Receded NPC ≥7.5 cm break or ≥10.5 cm recovery.
Diagnostic system: according to severity
i. Low suspect CI (exophoria at near ≥4 pd than at far and clinical sign one.
ii. High suspect CI (exophoria at near, and 2 signs or clinical sign 1 and 2 plus 3 or 4.
iii. Definite CI (all clinical signs must be present).