We have been researching the adverse effects of blue light from digital devices and artificial lighting since 2013 – there is a lot of scientific evidence about its effects on eyesight, physical and mental health, sleep and mood. At the back of our eyes, in the retina, exist both cone and rod photoreceptor cells that are responsible for light sensitivity. Recent research has shown that there is a third type of retinal photoreceptor and these are sensitive to blue light: intrinsically-photosensitive retinal ganglion cells (ipRGCs). These sparsely-situated receptors help differentiate between day and night, regulating our ‘sleep/wake’ cycles – known as circadian rhythms, with a flow-on effect to all our physiological functions.
Blue light received naturally and balanced with other colours, as part of full-spectrum sunlight, is necessary for optimal health. As diurnal beings, we are programmed to be outdoors while the sun is shining and asleep at night when it’s dark. Over the last 140 years, however, due to the invention and prolific use of artificial light, and much more recently the introduction of digital devices, we are exposed to significantly more artificial light during the day and at night. The light from digital devices and from light bulbs, LED lights and fluorescent tubes has a higher concentration of shorter-wavelength blue light than natural light and it is disturbing our health.
Blue light affects levels of the sleep-inducing hormone, melatonin, more than any other wavelength of light. Melatonin is created mainly by the pineal gland in the brain during darkness. It is profoundly affected by light and darkness and helps regulate other hormones whilst controlling the body’s circadian rhythm: an internal 24-hour ‘clock’. Tampering with the body’s circadian rhythm with artificial blue light exposure at night can exert a significant negative impact on health and has been implicated in depression, diabetes, immune problems, obesity, heart disease and cancer.
If you’re interested in optimal health, optimise your exposure to sunlight, minimise your exposure to artificial light and blue light, in addition to maintaining a healthy diet and lifestyle. We have a range of glasses in clear (daytime), orange (night-time) and red (night-time) lenses made in Sydney with easy-to-fit comfortable frames for both adults and children in our online shop – protect your eyes and physical and mental health.
Dr Jenny Livanos holistic optometrist offers personalised online/phone/email consultations which cover coaching in sunlight, blue light and artificial light specific to you – you can book in our online shop. Learn how to improve your relationship with natural and artificial light from morning to night – and improve the health of your family too. Jenny is the author of The Sunlight Diet – how to be healthy, happy and live longer!
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