|
| Convergence Insufficiency |
| Requires 1, 2, and 3 |
| 1. Near exophoria at least 4△ greater than distance exophoria |
| 2. Near point of convergence break point ≥6 cm |
| 3. Reduced near positive fusional vergence (break point ≤15△ or failed Sheard’s criterion) |
|
| Convergence Excess |
| Requires 1 |
| Plus at least 1 finding from 2 to 3 |
| 1. Near esophoria greater than distance esophoria by ≥4△ |
| 2. Reduced near negative fusional vergence (break point ≤7△ or failed Sheard’s criterion) |
| 3. Near vergence facility ≤12 cycle per minute |
|
| Divergence Insufficiency |
| Requires 1 or 2 + 3 |
| 1. Distance esophoria greater than near esophoria by ≥10△ |
| 2. Distance esophoria greater than near esophoria by ≥4△ |
| 3. Reduced distance negative fusional vergence (break point ≤4△ or failed Sheard’s criterion) |
|
| Divergence Excess |
| Requires 1 or 2 + 3 |
| 1. Distance exophoria greater than near esophoria by ≥10△ |
| 2. Distance exophoria greater than near esophoria by ≥4△ |
| 3. Reduced distance positive fusional vergence (break point ≤11△ or failed Sheard’s criterion) |
|
| Basic Esophoria |
| Requires 1 and 2 |
| Plus at least 1 finding from 3 to 4 |
| 1. Difference between near and distance esophoria ≤3△ |
| 2. Participant needs to be esophoric at both distant and near |
| 3. Reduced near or distance negative fusional vergence (near break point ≤7△ or distance break point ≤4△ or failed Sheard’s criterion) |
| 4. Near vergence facility ≤12 cycle per minute |
|
| Basic Exophoria |
| Requires 1 and 2 |
| Plus at least 1 finding from 3 to 5 |
| 1. Difference between near and distance exophoria ≤3△ |
| 2. Participant needs to be exophoric at both distant and near |
| 3. Reduced near or distance positive fusional vergence (near break point ≤15△ or distance break point ≤11△ or failed Sheard’s criterion) |
| 4. Near point of convergence break point ≥6 cm |
| 5. Near vergence facility ≤12 cycle per minute |
|
| Fusional Vergence Dysfunction |
| Requires 1 and 2 |
| Plus at least 1 finding from 3 to 4 |
| 1. No significant phoria at distance and near (distance: exophoria ≤2△ to orthophoria; near: exophoria ≤5△ to orthophoria) |
| 2. No other vergence dysfunction diagnosed |
| 3. Reduced near positive or negative fusional vergence (positive fusional vergence break point ≤15△ or negative fusional vergence break point (NFV) ≤7△ or failed Sheard’s criterion) |
| 4. Near vergence facility ≤12 cycle per minute |
|
| Accommodative Insufficiency |
| Requires 1 |
| 1. Monocular amplitude of accommodation ≥2 diopters below the minimum prediction (15-age/4) |
|
| Accommodative Infacility |
| Requires 1 |
| 1. Monocular accommodative infacility ≤6 cycle per minute |
|
