Richard Feinberg

“ This study is concerned with the latency period of the pupillary contraction to light and the relationship of this latency period to aging. Some findings on pupillary latency periods related to light intensity, as well as to myopes with mydriasis and to an individual with nerve conduction disease, are described. ”

“ The Grass Photic Stimulator (model PS-2) provided a high intensity flash of approximately one million peak candle power for 10 microseconds. The flash was seen by the left eye only, while measurements of latency period were obtained from the consensually reacting right pupil. For these measurements, the derivative of the Electronic Pupillograph scanner voltage was used rather than the analog voltage which represents the pupil
diameter ”

“ The latency values used at each intensity setting were means of 10 digital readings, a plot of which is shown in Figure 9. The standard deviation of the readings about each mean was approximately five milliseconds, and their standard deviations did not vary significantly from one intensity level to another.
LATENCY PERIOD OF PUPILLARY CONSTRICTION AND AGING
A scattergram (Fig. 7) of the average latency period by age shows a positive relationship (r=.54) between pupillary latency period and aging. As one grows older, his pupillary latency period increases. ”

“ A voltage of -0.35 was equivalent to a pupil contraction velocity of 3.5 mm. per second (manufacturer's specifications) .
One of the advantages of using the derivative pupil signal is that the same "Stop" level on the timer can be used for all subjects. Once the diameter of the pupil attains equilibrium (in darkness) , its derivative becomes zero and all measurements are taken from this zero point, i.e., all measurements are independent of the initial absolute diameter of the pupil or of the iris color. ”

“ Bender, W. R. G.: (1933) The effect of pain and emotional stimuli and alcohol upon pupillary reflex activity. Psychol. Monogr., 44:2:1-32.
Dolének, A.: (1960) Beitrag zur Pupillographie. Ophthalmologica, 139:76-83. ”