ACCOMODATIVE CONVERGENCE TO ACCOMODATION RATIO

I. GRADIENT METHOD:

AC/A = heterophoria with minus lenses - heterophoria with plus lenses

Difference in power of lenses

e.g. 14 – (- 2) = 16 = 4:1 [normal]

2 – (- 2) 4

II. HETEROPHORIA METHOD

AC/A = IPD + (n-d)

D

IPD in cm ; n = near phoria ; d = distance phoria; D = accommodation

e.g. 6 + ( - 5 – 0) = 4:1 [normal]

2.5