Calculators

Convergence

Accommodation, meter angles, AC/A ratio

Working distancecmInterpupillary distancecm

Accommodative demand

2.50D

Convergence

2.50MA

Convergence demand

15.5Δ

MA × PD (cm)

Reference

Normal AC/A ≈ 3–5 Δ/D. High AC/A → convergence excess / accommodative esotropia with near deviation.

Heterophoria method: AC/A = PD(cm) + (Δn − Δd)/Dn, eso positive, exo negative. Gradient: change in deviation ÷ lens power.

Hofstetter minimum amplitude = 15 − 0.25 × age.