Do green-blocking glasses enhance the nonvisual effects of white polychromatic light?

Soomin Lee,Tetso Katsuura,Naoshi Kakitsuba

doi:10.1186/s40101-018-0189-3

Abstract

BackgroundIt is well known that light containing the blue component stimulates the intrinsically photosensitive retinal ganglion cells (ipRGCs) and plays a role in melatonin suppression and pupillary constriction. In our previous studies, we verified that simultaneous exposure to blue and green light resulted in less pupillary constriction than blue light exposure. Hence, we hypothesized that the nonvisual effects of polychromatic white light might be increased by blocking the green component. Therefore, we conducted an experiment using optical filters that blocked blue or green component and examined the nonvisual effects of these lights on pupillary constriction and electroencephalogram power spectra.MethodsTen healthy young males participated in this study. The participant sat on a chair with his eyes facing an integrating sphere. After 10 min of light adaptation, the participant’s left eye was exposed to white pulsed light (1000 lx; pulse width 2.5 ms) every 10 s with a blue-blocking glasses, a green-blocking glasses, or control glasses (no lens), and pupillary constriction was measured. Then, after rest for 10 min, the participant was exposed a continuous white light of 1000 lx with a blue- or green-blocking glasses or control glasses and electroencephalogram was measured.ResultsPupillary constriction with the blue-blocking glasses was significantly less than that observed with the green-blocking glasses. Furthermore, pupillary constriction under the green-blocking glasses was significantly greater than that observed with the control glasses.ConclusionsA reduction in the green component of light facilitated pupillary constriction. Thus, the effects of polychromatic white light containing blue and green components on ipRGCs are apparently increased by removing the green component.

Highlights

Study participants Ten healthy young males (22 ± 0.5 years, 174.4 ± 3.6 cm, 63.2 ± 5.2 kg) with normal color vision participated in the experiment
Figueiro et al [16] found that simultaneous exposure to blue and green light resulted in reduced melatonin suppression, compared with monochromatic light exposure to blue or green light; this was referred to as a subadditive response to light
The % pupillary constriction in the green-blocking glasses condition, which contained the blue component of light but less green component, was significantly greater than the control glasses condition, which contained both blue and green components

Summary

Introduction

Study participants Ten healthy young males (22 ± 0.5 years, 174.4 ± 3.6 cm, 63.2 ± 5.2 kg) with normal color vision participated in the experiment. Each participant wore blue-blocking glasses, green-blocking glasses, and control glasses (no lens) in each condition, respectively These glasses contained only left-side lenses in order to measure the pupillary diameter (PD) of the right eye (Fig. 1a). We verified that simultaneous exposure to blue and green light resulted in less pupillary constriction than blue light exposure. We hypothesized that the nonvisual effects of polychromatic white light might be increased by blocking the green component. We conducted an experiment using optical filters that blocked blue or green component and examined the nonvisual effects of these lights on pupillary constriction and electroencephalogram power spectra. We verified that simultaneous blue and green light exposure resulted in less pupillary constriction than blue light exposure [6, 7]. The melatonin suppression response to polychromatic white light was significantly lower than to monochromatic blue light [17, 18]

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Conclusion