Do blue light blocking glasses really work?
Blue light blocking glasses have been developed to try and deal with the symptoms of eyestrain we experience when looking at screens for any length of time, but do blue light blocking glasses really work?
A new study (1) has shown that they probably don’t, and this article details why.
What is blue light and why are there concerns about it?
Blue light is part of the visible spectrum of light and the greatest source of it is the sun. Blue light is also artificially emitted from our digital devices and LED light bulbs. Blue is the shortest wavelength of visible light and the closest to UV light, and there were concerns that it was potentially harmful, particularly to the sensitive cells of the macula, which are the nerve cells of the central retina at the back of the eye that we use to see colours, faces and fine details.
Research has shown that high intensities of blue light can damage retinal cells but the majority of this research has been conducted in laboratories or on animal models using intense and prolonged light levels that we are not exposed to in everyday life.
The level of blue light emitted from computer screens and mobile devices is less than that absorbed when you step out into natural sunlight – and is below the international safety limits, so our phones and computers are not going to ‘fry our eyes’ because of the amount of light they emit. (1)
During the day, blue light can increase our alertness, responsiveness and boost our mood, but if we are exposed to it in the evenings it may affect the production of melatonin and therefore interfere with our sleep/wake cycle, which is an essential part of our health and wellbeing.
But blue light is beneficial during the day and is actually essential for our general health and wellbeing, so blocking all blue light during the day by wearing blue blocking glasses all the time may adversely affect your body clock or circadian rhythms.
What do blue light blocking glasses do?
Blue light blocking glasses have special coatings that filter out the blue light that is emitted from electronic devices such as TVs, computer screens, tablets and smartphones. Some of these devices – such as smartphones and tablets – also have blue light filters built in that you can 'switch on' which claim to do the same thing.
Current lenses may block 6% to 43% of blue light, and there is currently limited evidence that they actually work in terms of helping with eye strain. (2)
The Cochrane Review (3) published on 18 August 2023 included 17 studies that recruited 619 people in six countries and showed that in essence, we don’t really know whether blue-light filtering lenses have any advantage over regular lenses; we don’t know if they affect vision or sleep; and we don’t know if they help or if they harm (3).
What else can we do to protect our eyes and relieve any symptoms of eye strain?
The simple act of having our eyes checked by a health care professional and having glasses prescribed which optimise our vision may help with our symptoms of eye strain, whether the lenses block blue light or not.
Even if we don’t need glasses to see clearly, our eye muscles may become sore, tired and fatigued with overuse. We are not designed to stare at a computer screen for hours and hours and it is important to blink while we work to lubricate our eyes and rest them momentarily, and to adjust our focus regularly by looking away from the screen and into the distance for a moment to allow our eye muscles to relax.
Having other conditions that can cause ocular discomfort or difficulty seeing like dry eyes, blepharitis and cataracts diagnosed and treated correctly will also help our eyes feel better and see better. It is vital that we have regular eye health checks for all these reasons and also to pick up diseases like glaucoma and macular degeneration that may cause no symptoms in the early stages, until it is too late.
Staying hydrated and blinking frequently will help to keep our tear film healthy and our eyes moist. If our eyes are dry, we can lubricate them with preservative-free eye drops. Turning down the brightness of our computer screens, using a programme that reduces the amount of blue light emitted from the screen, or even and especially turning the screen off completely an hour before bedtime may all help us settle when it is time to go to sleep.
What else can we do to improve our quality of sleep?
What we do with our eyes is just one aspect of our movements as we wind down at the end of the day to prepare for sleep. In fact, the way we live the whole day is what truly determines the quality of our sleep at night. And sleep is such a vital part of our day. In sleep we dream and heal, while our body is restored from the rigours of the day and revitalised for the next. The quality of our sleep determines the quality of our day, and the quality of our day determines the quality of our sleep. And that quality is affected by everything we think, say and do. This includes what we eat and drink, how we think and speak about ourselves and others, and how we move these precious bodies of ours. In the end, everything comes back to the way we live, which is and always has been our true medicine.
1. Study Questions if Blue Light Blocking Glasses Really Work
2. Do blue light blocking glasses actually work?