We have been interested in and researching the adverse effects of blue light from digital devices and artificial lighting for more than 10 years – there is a lot of scientific evidence about their detrimental effect on physical and mental health, sleep, mood and directly and indirectly on eyesight. We have a range of glasses in clear, orange and red lenses in easy-fit comfortable frames for both adults and children (https://naturaleyecare.com.au/product-category/blue-light-blocking-glasses-and-fitovers-for-adults-and-kids/) – protect your eyes and physical and mental health with these products. These are made in our Sydney lab to order. For additional types and lighting we are affiliated with blockbluelight – our special link is https://www.blockbluelight.com.au/?aff=191 and for 10% off use our code “naturaleyecare” – we especially love their portable night lights and amber and red globes.
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 balance with other colours, as part of 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 body’s rhythm, sleep patterns & health.
Blue light affects levels of the sleep-inducing hormone, melatonin, more than any other wavelength of light. Melatonin is created by the pineal gland in the brain during darkness and not produced during daylight. It is profoundly affected by light and darkness. Melatonin helps regulate other hormones whilst controlling the body’s circadian rhythm: an internal 24-hour ‘clock’. Tampering with the body’s circadian rhythm with blue light exposure at night can have a negative impact on health and has been implicated in depression, diabetes, immune problems, obesity, heart disease and cancer.
Nowadays it is common to come home after a long day at work or school and relax by surfing the internet on our laptops, reading on an e-reader, playing games on our tablets, catching up with social media on our smart phones and/or watching television on our large screens – or a combination of these at the same time! Those who regularly use these devices report symptoms like blurry vision, headaches, fatigue, light sensitivity, watery/dry/itchy eyes and neck and back pain. There is an increased risk for cell damage leading to eye diseases like macular degeneration and cataracts.
We all need protection from blue light exposure at night, but some people are more vulnerable to its negative effects: • Office workers in front of computers all day, with high exposure to fluorescent tubes and LED lights, coupled with minimal sunlight exposure
• Teenagers and children who use digital devices late at night for study and personal use – they may have trouble getting to sleep, waking up easily and have issues with mood and concentration
• Shift workers – studies have linked working night shifts, and subsequent exposure to light and blue light, to several types of cancer (breast, prostate), diabetes, heart disease and obesity
• People already more at risk for eye diseases like macular degeneration, including having a family history, smoking, cardiovascular issues, diabetes or poor diet
• Those with intra-ocular lenses who have had cataracts removed – exposed to more blue light penetration through to the retina.
Tips for better sleep and health:
• Get the morning sunshine through your eyes eg. have breakfast outside; go for a walk, facing the sun
• Expose yourself to bright natural light during the day – take regular sun breaks; have your lunch breaks outdoors
• Sunglasses may limit your eyes’ access to full sunlight for an optimal body clock and health. Wear a hat if you need to or sit in shade
• Have lots of breaks away from your digital screens. Try the 20-20-20 rule: look up every 20 minutes to 20 feet away (6 metres) for 20 seconds: and take a physical break away from your work every 20 minutes! Turn your screen brightness down and position screens and smart phones further away from your eyes
• If you wear glasses for digital device use, opt for blue-light filter in these glasses which will block about 30% of blue light
• Install an app that reduces blue light at night on your laptop and smartphone; for example, f.lux and Iris. I-Phone users now have a blue-light reduction feature called ‘Night Shift’
• Avoid using digital devices for two to three hours before going to bed. Use 100% blue-blocking fit-over glasses in the evening (amber or red), especially if using digital devices. Wear these glasses continuously before bedtime – with all TV viewing, computer, tablet, e-reader and smartphone usage. Remove these only after all lights have been switched off and you’re in bed!
• Dim general lighting in the evening
• When you feel sleepy, go to bed – listen to your body!
• Sleep in complete darkness (avoid smart phones, night lights and digital clocks in the bedroom)
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. Dr Jenny Livanos holistic optometrist offers personalised consultations in The Sunlight Diet which covers coaching in sunlight, blue light and artificial light specific to you.