Many of us are aware that blue light exposure can impact our sleep. Many studies have clearly established the negative impact that blue light exposure at night has on melatonin release and sleep[1],[2],[3]. One study found that blue light exposure during the day had a positive impact on supporting circadian rhythm[1]. However, they cautioned against exposure to blue light at night, and recommended use of blue light blocking tools, such as an “anti-blue light glasses or screen cover”. This study also highlighted the detrimental effects of prolonged blue light exposure on eye health. Although blue blocking devices are often recommended, a systemic review looking at evidence for the effects of blue filtering lenses found no conclusive evidence that these lenses had a positive effective on improving sleep quality[4].
On the other hand, some research shows that blue light can have positive effects on mental health, including seasonal affective disorder and anxiety[2]. Some studies also indicated that exposure to blue light can increase cognitive function[3]. Some takeaway strategies here include switching to paper-format for reading at night, maintaining blue light exposure during the day and reducing it at night, and paying attention to eye strain and taking breaks. It is also helpful to have time boundaries around phone use during the day, and a cut off time at night. Even with blue light filters, using your phone at night can cause stimulation in other ways, and gifting yourself some device-free time in the evening can support with sleep and mental health.
All in all, this blog post is not intended to scare you away from your devices. More so, I hope to encourage reflection around using devices mindfully. I’ve included reference articles throughout this post, which you can find by searching scholar.goolge.com. I would also be happy to answer any questions you might have. I can be reached at erinspencerot@gmail.com.
[1] Zhao, Z. C., Zhou, Y., Tan, G., & Li, J. (2018). Research progress about the effect and prevention of blue light on eyes. International journal of ophthalmology, 11(12), 1999. [2] Holzman, D. C. (2010). What’s in a color? The unique human health effects of blue light. [3] Tosini, G., Ferguson, I., & Tsubota, K. (2016). Effects of blue light on the circadian system and eye physiology. Molecular vision, 22, 61. [4] Lawrenson, J. G., Hull, C. C., & Downie, L. E. (2017). The effect of blue‐light blocking spectacle lenses on visual performance, macular health and the sleep‐wake cycle: a systematic review of the literature. Ophthalmic and Physiological Optics, 37(6), 644-654.