Blue light is not new by any means, but the prevalence of blue light in our daily lives has increased exponentially with the widespread popularity of blue light-emitting devices such as computers and smartphones, as well as energy-efficient LED light bulbs and fluorescent lighting. With a significant number of people carrying a smartphone and spending a good portion of their day in front of a computer screen, and with LED light bulbs increasingly becoming the standard for homes, offices and business settings, it’s a good idea to know how blue light affects your eyes and the benefits of blue light blocking glasses and sunglasses.
Blue light is part of the visible light spectrum. It has a short wavelength, meaning it is a higher-energy wavelength. Blue light waves are the among the shortest, highest energy wavelengths in the visible light spectrum. Because they are shorter, these “Blue” or High Energy Visible (HEV) wavelengths flicker more easily than longer, weaker wavelengths. This kind of flickering creates a glare that can reduce visual contrast and affect sharpness and clarity. This flickering and glaring may be one of the reasons for eyestrain, headaches, physical and mental fatigue caused by many hours sitting in front of a computer screen or other electronic device. Studies suggest that 60% of people spend more than 6 hours a day in front of a digital device.
Blue light occurs naturally in sunlight and is an important part of the sleep-wake cycle.
Blue light tells our body clock that its daytime, think of the color of the sky, its blue. This blue light tells our brain we need to release the correct hormones to be active during the day, these are cortisol, dopamine and serotonin. When the sun sets, darkness tells our body clock that its night-time and we need to relax and unwind, ready for sleep. The absence of blue light after sunset allows our bodies to turn the serotonin made in the gut during the day into melatonin which helps us sleep deeper and longer.
This is all very well but in today’s world we create “artificial daytime” after sunset. When it gets dark we turn on our house lights, switch on our TV and open our cell phones. All of these things, and more, contain HEV blue light. This blue light sends a light message to our body clock which tells it that it is daytime, not to unwind and to be active. This is why as a global population we have seen a rapid surge in cases of sleep disturbance issues. Harvard Health has even said that lack of good quality sleep can lead to issues such as diabetes, cancer, depression and obesity.
Let me know if you’ve tried blue light blocking glasses? Your thoughts?