proximal vergence 在gradient
AC/A及calculated
AC/A間的作用
To estimate proximal vergence clinically
PD60mm
Distance phoria = 4 eso
Near phoria = 10 eso
Phoria
through +1.00 at near = 5 eso
gradient AC/A=5△/D
calculated AC/A=8.4△/D
proximal vergence=8.5.
The calculated AC/A ratio is usually larger
than the gradient AC/A because of the effect of proximal vergence and the lag
of accommodation.
