Comparison of Pupillary Responses to Low and High Frequency Lighting

Using infrared pupillometry the pupil sizes of 24 healthy young adult subjects were compared under indirect illumination from four different light sources operating at either the 60 Hertz line frequency or at a high frequency of approximately 30 Kilohertz. Several different luminance levels were used in the frequency comparison ranging from 5 to 160 candelas per square meter (cd/m²). Under conditions where pupil size differences have been observed due to both spectral composition of the lamps and luminance changes, no differences were found between high and low frequency operation within the accuracy of these experiments.