Effect of tinted lenses’ color based on pupil and heart rate variability

Abstract

We investigated the effects of tinted lenses’ color on the autonomic nervous system, based on pupil diameter and heart rate variability. The study participants were 14 healthy young adults. For the tinted lenses, three colors were selected: green, grey, and orange. Examinations were performed in a dark adaptation room. The participants were in a supine position and were asked to look fixedly at a cross marked in the center of a white background on a luminescent display (9.7-inch iPad) positioned 30 cm from their eyes. Pupil diameter and heart rate variability were measured with an infrared pupilometer (Newopto Corp.) and a Reflex Meijin system (Crosswell Co., Ltd.), respectively, before, during, and after wearing the tinted lenses. Pupil constriction after lens-wearing compared with lens-wearing was induced by the three tinted lenses, and after green lens-wearing, pupil was greater than before lens-wearing. Pupil dilation during lens-wearing compared with before lens-wearing was induced by the orange tinted lens. Heart rate variability analysis revealed no significant differences between the before, during, and after lens-wearing periods for any color. The color of the tinted lenses induced changes in pupil diameter but had no effect on heart rate variability.