ABSTRACT
Phase 1 1. McDonald chart 2. Brock’s string: start at a close range, where it is
easy for the patient to converge accurately on the ball, then three bead jump
3. GTVT medium 4. Multiple-choice vergence (MCV; VTS)
(base in [BI]) 5. Two-finger jump duction
Phase 2 1. MCV jump ductions (BI and base out [BO]) 2. Clown vectogram (BI) 3. Cohen chart with BI prism 4. GTVT small with BI prism (Tables 8.1
through 8.3)
Phase 3 1. BIM/BOP (±1.00 up to ±2.00) with a clown
vectogram/spirangle vectogram 2. Aperture rule (BI; double aperture) 3. Lifesavers/eccentric circles (BI)
Phase 1 1. Brock’s string 2. Two-finger jump duction 3. Pointer in the straw 4. Computer MCV (BO) 5. Clown vectogram (BO with localization)
Phase 2 1. Spirangle (BO with localization) 2. Dynamic reader with BO prism 3. GTVT with BO prism
Phase 3 1. Aperture rule (BO; single aperture) 2. BIM/BOP (±1.00 up to ±2.00) with a clown
vectogram/spirangle vectogram 3. Lifesavers/eccentric circles (BO)
1. Two-finger jump duction 2. Brock’s string push up and Brock’s string jump
ductions
3. GTVT medium 4. Pointer in the straw 5. Barrel card 6. Fusion faces 7. Eccentric circles/lifesaver cards (opaque)*
1. Two-finger jump duction 2. McDonald chart 3. Brock’s string pull away, Brock’s string jump
ductions 4. GTVT medium 5. Eccentric circles/lifesaver cards (clear)†
Purpose To decrease suppression and improve binocularity
Equipment ● GTVT chart (small, medium, or large) ● R/G glasses
Set-up ● Place the GTVT chart at the eye level. ● Have the patient stand at a proper distance.
