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.
How do your eyes feel?
If you’ve been looking for blue light glasses because you’ve noticed a difference in how your eyes feel lately, then we recommend you have an eye exam where you will receive professional advice.
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 colour 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, 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 enter 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.
According to the Canadian Association of Optometrists, "There is no clinical evidence that artificial blue light at low intensity and shorter exposure periods is harmful to the eye." The Association recognizes that a large portion of our time is spent using different types of digital screens, which can cause eye strain and ultimately eye fatigue. It is therefore recommended to use the 20-20-20 rule. Every 20 minutes, look away from your screen and focus on a target 20 feet away for 20 seconds in order to allow for your eyes to relax and take a break.3
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.4
Blue light filtering glasses lens options
- 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.com/doi/full/10.1111/opo.12414 [accessed 07/08/2020]
- 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).
- The Canadian Association of Optometrists, Blue Light: is there a risk of harm. [online]. Available at: https://opto.ca/health-library... [accessed 31/10/2022]
- Khurana, Rahul, MD., ‘Are Computer Glasses worth it?’, American Academy of Ophthalmology. (2017). [online]. Available at: https://www.aao.org/eye-health/tips-prevention/are-computer-glasses-worth-it [accessed 07/08/2020]
- The Canadian Association of Optometrists, AMD (Age-related macular degeneration). [online]. Available at: https://opto.ca/eye-health-library/amd-age-related-macular-degeneration [accessed 01/12/2022]