A Deep Dive into Light and Circadian Rhythms

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In a groundbreaking study by researcher Leena Tähkämö, the critical connection between light exposure and the human circadian rhythm takes center stage. Published in The Journal of Biological and Medical Rhythm Research, this systematic review underscores the pivotal role of light in our lives while shedding light on the potential health and environmental impacts of artificial light.

Unveiling the Impact of Light on Circadian Rhythm

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Tähkämö’s review, based on an extensive analysis of 128 articles, delves into the effects of mistimed light exposure on key aspects of the circadian rhythm, with a particular focus on melatonin secretion and REM sleep. The findings are enlightening, revealing that a mere two-hour exposure to blue light in the evening significantly suppresses melatonin, a crucial hormone regulating sleep-wake cycles.

Zenni’s Contribution to Circadian Well-being

Amidst growing concerns, Zenni Optical is committed to addressing the potential harm caused by blue light exposure, especially during evening hours. Our innovative Blokz blue light blocking lens offers a clear solution, designed with special monomers to mitigate the impact of high-energy visible light. Additionally, for heightened protection, our Blokz Plus blue light blocking lens, featuring a soothing yellow tint, acts as a shield against extra blue light emitted from screens—an ideal “night mode” for your glasses.

In concluding our exploration of light and circadian rhythms, Leena Tähkämö’s groundbreaking study emphasizes the crucial link between light exposure and our biological rhythms. Zenni Optical responds to these findings with a commitment to circadian well-being, offering innovative Blokz lenses that may potentially help mitigate the impact of harmful blue light during evening hours. Illuminate your journey to healthier living with Zenni’s transformative eyewear solutions.

Explore Blokz Blue Light Blocking Lenses


Leena Tähkämö, Timo Partonen & Anu-Katriina Pesonen (2019) Systematic review of light exposure impact on human circadian rhythm, Chronobiology International, 36:2, 151-170, DOI: 10.1080/07420528.2018.1527773

About the Author: Dr. Sophia Moh, OD, ABOC

Dr. Sophia Moh, OD, is an optometrist based in the Bay Area, California. She holds a doctorate from UC Berkeley School of Optometry and has worked in various eye care settings, including primary care optometry, general ophthalmology, community health clinics, and Veterans Affairs. Dr. Moh is dedicated to improving global vision health by making high-quality, affordable eyewear accessible to all. She is also a certified American Board Optician (ABO) and actively contributes to optical education through training and lectures.