speed of the reflex

Question 1

What can the reflex speed be shown as?

Answer 1

Speed of Reflex = 2 (W - X) / -K
- W is the working distance (-1.50D)Wh
X is the immediate source location in Dioptres
K is the subject’s ametropia

Question 2

Summary

Answer 2

the speed and appearance of the reflex in spherical ametropia can be explained by geometrical optics
The most sensitive measure of reversal is obtained with diverging light (slide down)
Converging light will swap the reflex movements