Sunlight, Artificial Light and Blue Light
We have been researching the adverse effects of blue and artificial light from digital devices such as mobile phones, computers, tablets and TV’s since 2013. There is now a substantial body of scientific evidence demonstrating their negative impact on eyesight, physical and mental health, sleep quality and mood.
At the back of the eye lies the retina, which contains cone and rod photoreceptor cells responsible for detecting light and enabling vision. More recent research has identified a third type of photoreceptor known as intrinsically photosensitive retinal ganglion cells (ipRGCs). These specialised cells are particularly sensitive to blue light and play a crucial role in regulating our internal body clock.
These receptors help the body distinguish between day and night, regulating our sleep–wake cycles, also known as circadian rhythms. These rhythms influence a wide range of physiological processes, including hormone production, energy levels, immune function and mental wellbeing.
The Role of Natural Sunlight
Blue light wavelengths, when received naturally as part of full-spectrum sunlight during the day, are essential for good health. As diurnal beings, humans are biologically programmed to be exposed to natural daylight during waking hours and to experience darkness at night while sleeping.
However, over the past 140+ years—since the invention of artificial lighting—and more recently with the widespread use of digital devices, we are now exposed to artificial light almost continuously. Light emitted from screens, LED lighting, fluorescent tubes and modern light bulbs contains a disproportionately high concentration of short-wavelength blue light compared to natural sunlight. This imbalance is having a significant impact on our sleep patterns and overall health.
Unlike artificial lighting, sunlight is dynamic and constantly changing throughout the day, providing a balanced spectrum of light that supports optimal biological function.
Blue Light, Melatonin and Circadian Rhythm Disruption
Blue light has a particularly strong effect on melatonin, the hormone responsible for initiating sleep. Melatonin is primarily produced by the pineal gland in the brain in response to darkness. It plays a vital role in regulating the body’s circadian rhythm—our internal 24-hour “clock”—as well as influencing other hormonal systems.
Exposure to artificial blue light at night suppresses melatonin production and disrupts this natural rhythm. Over time, this disruption can negatively affect sleep quality and has been associated with a range of health concerns, including eye issues, depression, diabetes, immune dysfunction, obesity, cardiovascular disease and even certain cancers.
Practical Steps for Better Light Hygiene
If you’re interested in improving your health, it is essential to optimise your exposure to natural sunlight during the morning and throughout the day, while minimising exposure to artificial and blue light—especially in the evening and at night. Our consultations also include advice on best light practices for better eye and general health and wellbeing.
We offer specially designed glasses and fitovers in both clear (daytime) and red (night-time) lenses. These are made in Sydney and feature comfortable, one-size-fits-all frames suitable for both adults and children. We also stock portable red light lamps that are easy to use. These products are designed to help protect your eyes, support your circadian rhythm and promote better physical and mental health.
See our online store for these products or call us on 0402410821 or email us at naturaleyecare.com.au