Characterization of Visual Symptomatology Associated with Refractive, Accommodative, and Binocular Anomalies

Table 1

Clinical signs used in the study for diagnosing accommodative and binocular anomalies (AA: accommodative amplitude; MAF/BAF: monocular/binocular accommodative facility; MEM: monocular estimate method; PRA/NRA: positive/negative relative accommodation; PFV/NFV: positive/negative fusional vergence; NPC: near point of convergence; VF: vergence facility; Δ: prism diopters; D: diopters; cpm: cycles per minute; BO: base-out; BI: base-in).

Dysfunction	Fundamental sign	Complementary sign
Accommodative dysfunctions
Accommodative insufficiency	Reduced AA: 2.00 D < minimum AA (15–0.25 × age)	MAF < 6 cpm with −2.00 D lenses
		BAF < 3 cpm with −2.00 D lenses
		MEM > 0.75 D
		PRA < 1.25 D
Accommodative excess	MAF < 6 cpm with +2.00 D lenses	PRA ≥ 3.50 D
		BAF < 6 cpm with +2.00 D lenses
		MEM < 0.25 D
		NRA < 1.50 D
Accommodative infacility	MAF < 6 cpm with ±2.00 D lenses	BAF < 3 cpm with ±2.00 D lenses
		PRA < 1.25 D
		NRA < 1.50 D
Binocular dysfunctions
Convergence insufficiency	Significant exophoria at near vision (≥6 Δ), greater than far vision	PFV at near ≤ 11/14/3 Δ
		NPC ≥ 6 cm
		VF < 13,4 cpm with 12 Δ base-out prism
		BAF < 3 cpm with +2.00 D lenses
		MEM < 0.25 D
		NRA < 1.50 D
Convergence excess	Significant esophoria at near vision (≥1 Δ), greater than far vision	NFV at near ≤ 8/16/7 Δ
		VF < 13.4 cpm with 3 Δ base-in prism
		BAF < 3 cpm with −2.00 D lenses
		MEM > 0.75 D
		PRA < 1.25 D
Divergence excess	Significant exophoria at far vision (≥4 Δ), greater than near vision (the difference must be >5 Δ)	PFV at far ≤ 4/10/5 Δ
		PFV at near ≤ 11/14/3 Δ
		NPC ≥ 6 cm
		VF < 13,4 cpm with 12 Δ base-out prism
		BAF < 3 cpm with +2.00 D lenses
		MEM < 0.25 D
		NRA < 1.50 D
Basic esophoria	Significant esophoria at far and near vision of equal amount (deviations within 5 Δ of one another are considered equal)	NFV at far ≤ /3/1 Δ and at near ≤ 8/16/7 Δ
		VF < 13.4 cpm with 3 Δ base-in prism
		BAF < 3 cpm with −2.00 D lenses
		MEM > 0.75 D
		PRA < 1.25 D
Basic exophoria	Significant exophoria at far and near vision of equal amount (deviations within 5 Δ of one another are considered equal)	PFV at far ≤ 4/10/5 Δ and at near ≤ 11/14/3 Δ
		NPC ≥ 6 cm
		VF < 13,4 cpm with 12 Δ base-out prism
		BAF < 3 cpm with +2.00 D lenses
		MEM < 0.25 D
		NRA < 1.50 D
Fusional vergence dysfunction	PFV and NFV reduced at far and near vision or VF < 13.4 cpm with both prisms of the combination used of 12 BO/3 BI	BAF < 3 cpm with ±2.00 D lenses
		PRA < 1.25 D; and NRA < 1.50 D