Maximum amplitude of accommodation as a function of the frequency (A) or current (B) of the stimulus.

A: The frequency was varied and the current was fixed at 1 mA. B: The current was varied and the frequency was fixed at 40 Hz. One or 2 drops of phenylephrine hydrochloride was instilled prior to the measurements. The maximum amplitude of accommodation is the average of four eyes of four cats (Cat #2, #4, #6, #7). Error bars indicates standard deviations. Monophasic square pulses at a fixed pulse width of 0.5 ms were applied to the lateral, medial, or both branches of the short ciliary nerve.