Effects of Bright Light with Reduced Blue Light on Sleepiness on Rising: A Small Exploratory Study

Abstract

Bright light therapy is a treatment modality for seasonal affective disorder and circadian rhythm disorders in which artificial light of 2,500 lux or higher at the eye is effective. Although short-wavelength visible light is more effective than long-wavelength visible light, it may be hazardous to the retina. Recently, light-emitting diodes (LEDs) have been used as the light source in bright light therapy apparatuses. We developed goggles for bright light therapy equipped with LEDs as the light source. The aim of this study was to examine the efficacy and safety of our goggles when emitting 10,000-lux light with its short-wavelength light content reduced by 30% or 50% (denoted as 30%-cut and 50%-cut light, respectively, henceforth). Six healthy young males participated in this study. They were administered no light, 50%-cut light, and 30%-cut light for 30 min early in the morning for 4 days each. Subjective sleepiness and sleep quality were evaluated by the Stanford Sleepiness Scale (SSS) and the Oguri–Shirakawa–Azumi sleep inventory MA version (OSA-MA), respectively. Subjective sleepiness evaluated by the SSS and the subscale of the OSA-MA significantly decreased with 30%-cut light compared with no light. Psychomotor performance evaluated by a calculation task improved with the 30%-cut light, although not significant after multiple comparisons were considered. No abnormality was found by ophthalmoscopy and the vision test. In conclusion, our goggles with 30%-cut light may be safe and have an awakening effect.

Potential Protective Role of TRPM7 and Involvement of PKC/ERK Pathway in Blue Light–Induced Apoptosis in Retinal Pigment Epithelium Cells in Vitro

“…Light radiation via targeted lasers has wide therapeutic applications, for instance, photobiomodulation (PBM) therapy 36 and antimicrobial photodynamic therapy (aPDT) 37 . Blue light can also eliminate community-acquired methicillin-resistant Staphylococcus aureus (MRSA) from the infected skin abrasions in mice, 38 and alter the inflammatory and immunoregulatory phenotypes of human leukocytes 39,40 . On the other hand, blue light–induced photochemical damage causes photoreceptor cell death, the severity of which depends on the light intensity, exposure time, and wavelength 41,42 …”

The association between the subjective quality of sleep and the phase of a 90-minute periodic signal for the wake-up support system

“…Table I describes the obtained 11 parameters. In addition, after the subject wokeup, a questionnaire was completed regarding his/her subjective quality of sleep using the OSA-MA evaluation [12][13][14][15][16]. Evaluation factors are divided into five categories: OSA-MA 1, OSA-MA 2, OSA-MA 3, OSA-MA 4, and OSA-MA 5.…”

“…In this sleep experiment, the subjective quality of subjects was evaluated using the OSA-MA [12][13][14][15][16]. The score was calculated by dividing it into five categories using the written questionnaire after wake-up.…”

“…In the sleep experiment, the subjective quality of the subject has been often evaluated using the Oguri-Shirakawa-Azumi sleep inventory, middle-aged and aged version (OSA-MA) [12][13][14][15][16]. The OSA-MA is a questionnaire designed for self-reported sleep quality at night on the next morning [12].…”

Blue Light Therapy and the Circadian Rhythm: Effect on Southern California High School Students

“…Although blue-light may be viewed as harmful (as in electronics mainly) for its effect on sleep, light has been shed on the positive side of blue-light with a promising change in the therapy field (Miura 2018). If blue-light is used at appropriate times, it can be a useful tool.…”