If you’ve ever worried about the effect of digital screens on your eyes, then you may have heard about ‘blue light’, and perhaps even searched for ways to protect your eyes against it. Blue light glasses (or blue light blocking glasses) are becoming more popular than ever due to claims that they can protect your eyes against potential damage — but how effective are they at keeping your eyes healthy? Here, we’ll take a closer look into the scientific research behind blue light glasses, and whether they actually work.
What is blue light?
Sunlight contains many types of coloured light (including red, orange, yellow, green, blue, indigo and violet), each with a different wavelength and energy level. Combined, this spectrum of coloured light rays creates what we call ‘white light’ (or sunlight).
Blue light is just one type of coloured within this light spectrum — generally defined as ‘visible light’. This means that it has a short wavelength and high energy levels. Levels of blue light are emitted from a range of different light sources, the largest being the sun, which is where we get most of our exposure to it. However, there are also many man-made sources, and in recent years, blue light has gained notoriety because of its link to digital screens. Computers, tablets, smartphones and other digital screens all emit blue light. Although this is only a fraction of that emitted by the sun, however the amount of time people spend using these devices and the proximity of these screens to the eyes has caused some concern about potential long-term effects of blue light on eye health.
What does blue light do to your eyes?
Blue light has a short wavelength, which makes it very easy for it to penetrate the eyes. This means that almost all visible blue light rays can pass through the cornea and lens to the retina (the lining of the back of the eye). While there is little research to support this, some experts have suggested that too much exposure to blue light has the potential to damage the light-sensitive cells in the retina. One animal study also found that blue light damage may cause phototoxic retinal damage.1
However, while it is true that digital screens do emit some blue light, research has found that the level of blue light exposure from screens is significantly lower than that from natural daylight — and neither levels approach eye safety limits.2 This means that the potential blue light damage caused from digital screens is likely to be very little, if any at all.
What are blue light glasses?
Blue light glasses (sometimes called blue light blocking glasses) are glasses that contain lenses specifically designed to reduce the amount of blue light that reaches the eye. These lenses filter blue light rays to help prevent them from entering your eye and causing potential damage. Usually, blue light lenses have a slight yellow tint (to counterbalance the blue light), but you can’t usually notice this.
Do blue light glasses work?
While blue light blocking glasses are effective at reducing the amount of blue light that enters the eyes, there is no current research to suggest that this can improve or protect the health of your eyes. Put simply, there is no scientifically-proven benefit of wearing blue light blocking glasses for your eye health.
As The College of Optometrists states: ‘The best scientific evidence currently available does not support the use of blue-blocking spectacle lenses in the general population to improve visual performance, alleviate the symptoms of eye fatigue or visual discomfort, improve sleep quality or conserve macula health.’ 8
Do blue light blocking glasses help with eye strain?
Some people may consider getting blue light glasses because of claims that they can help to reduce eye strain when using digital devices. However, there is not enough research evidence to suggest that blue light causes digital eye strain in the first place. When using digital screens, eye strain can occur for a number of reasons. If you spend too long concentrating and looking at a screen, then your eyes can become fatigued. Also, your eyes have to shift focus constantly while looking at screens, and sitting too close can strain your eye muscles as they try to focus on such a close image. If you wear glasses, glare reflected onto your digital screen or glasses lenses from surrounding light sources (such as bright office lights, or a nearby window) can also cause your eyes to squint and strain.
It’s easy for these issues to be labelled as a result of blue light, however, it’s more likely that these problems are simply caused by the overuse of digital devices, and not blue light itself. The majority of times, eye fatigue is due to digital eye strain, and blue light damage is rare, if it occurs at all.7
Do blue light glasses prevent retinal damage?
Cell culture experiments and animal studies have determined that blue light can damage the retina of your eye.3, 4, 5, 6 However, there is not enough research evidence to suggest that blue light absorbing devices (such as blue light lenses) are beneficial for reducing the risk or progression of retinal conditions such as age-related macular degeneration (AMD).1
Alongside this, many regulations have been put in place to limit the amount of blue light emitted by everyday objects. Due to these safety limits, the levels of blue light that are emitted from objects like light bulbs and digital screens are not high enough to cause retinal damage. This means that wearing blue light blocking glasses when using digital screens is not really necessary.
What are some alternatives to blue light glasses?
Instead of resorting to blue light glasses, there are a number of other ways that have been proven to help reduce digital eye strain.
Screen use top tips
Practising self-care is one of the simplest ways to prevent and reduce eye strain. For instance, taking regular breaks and following the 20-20-20 rule (for every 20 minutes you look at a device, take a 20-second break looking at something 20 feet away) can help to give your eyes a rest from close-up vision and allow them to focus on different distances. You can also adjust your computer or screen settings to ensure that the brightness and contrast are balanced correctly. If you find yourself focusing on small fonts or looking in detail at your screen, try making things larger by working at 125%-150% zoom. This will reduce the amount of work your eyes need to do to focus on very small text and images.
Glasses for screen use
Another way to make your eyes more comfortable while using digital screens is to wear glasses that have an anti-glare coating on the lenses. These can help to limit the impact of light reflections on your eyes, ultimately reducing strain. For instance, our UltraClear SuperClean lens features a specialist anti-reflection treatment that helps to reduce reflections on your glasses lenses and limit screen glare. They are also smudge and scratch resistant, which help to give you an overall clearer view of your screen.
Varifocals for screen-use
Varifocal lenses are another option, especially if you are over 40 and have noticed that your eyesight at all distances is beginning to worsen. Varifocal lenses seamlessly transition between viewing close up, far away and everything in between, making them ideal if you have different prescriptions for distance vision, using a digital device or reading. Unlike traditional varifocals, however, our SuperDigital lenses have been designed with digital screens in mind. The near zone even caters for the closer, higher position we hold our mobile phone, and they also include our UltraClear SuperClean help to reduce the effects of screen glare.
Many people are concerned about the effects of using a computer or smartphone on their eyes. If you are concerned, remember to take regular breaks. If you feel you are experiencing eye strain or discomfort, contact your local Specsavers to arrange a sight test and get the most up to date and evidence-based help to protect your eyes and reduce eye strain.
1. Downie, Laura., ‘Blue-light filtering ophthalmic lenses: to prescribe or not to prescribe?’, Ophthalmic and Physiological Optics: The journal of the college of optometrists, 37, 6. (2017). [online] Available at: https://onlinelibrary.wiley.co... [accessed 07/08/2020]
2. O'Hagan JB, Khazova M & Price LL. ‘Low‐energy light bulbs, computers, tablets and the blue light hazard’. Eye (London). 30. pp. 230–233. (2016).
3. Davies S, Elliott MH, Floor E et al . ‘Photocytotoxicity of lipofuscin in human retinal pigment epithelial cells’ Free Rad Biol Med, 31. pp. 256-265. (2001).
4. Sparrow JR, Miller AS & Zhou J. ‘Blue light‐absorbing intraocular lens and retinal pigment epithelium protection’ in vitro. J Cataract Refr Surg, 30. pp. 873–878. (2004).
5. Kuse Y, Ogawa K, Tsuruma K, Shimazawa M & Hara H. ‘Damage of photoreceptor‐derived cells in culture induced by light emitting diode‐derived blue light’, Sci Rep, 4. 5223. (2014)
6. Noell WK, Walker VS, Kang BS & Berman S., ‘Retinal damage by light in rats’, Invest Ophthalmol Vis Sci, 5. pp. 450–473. (1966).
7. Khurana, Rahul, MD., ‘Are Computer Glasses worth it?’, American Academy of Ophthalmology. (2017). [online]. Available at: https://www.aao.org/eye-health... [accessed 07/08/2020]
8. The College of Optometrists, Blue blocking spectacle lenses (2018). [online]. Available at: https://www.college-optometris... [accessed 07/08/2020]