*Disclaimer* This program offers health and nutritional information and is for educational and informational purposes only. You should not rely on this information as a substitute for, nor does it replace professional medical advice, diagnosis, or treatment. If you have any concerns or questions about your eye health, you should always consult with a professional. Do not disregard, avoid, or delay obtaining medical or health-related advice from your health-care professional because of something you may have read on this site.
How to identify if we are a victim of blue light?
The electromagnetic spectrum where we learn about radiation and different wavelengths, some of them like x-rays, UV rays, and infrared rays are invisible to the human eye. There is a spectrum though, that is visible to the human eyes and that is the Visible Light Spectrum were depending on the wavelength will be seen as the different colors- e.g. short = 380nm seen as purple-blue light, long = 700nm seen as red light(1)
Light rays that have relatively long wavelengths contain less energy(2), and those with short wavelengths have more energy which basically means that it scatters more and may cause more glare.
So what about white light? White is not seen here in the visible spectrum because it is emitting a mixture of all the wavelengths in the visible spectrum, which is why occasionally we see rainbows when white light gets reflected off different surfaces(3). Blue light is part of the light spectrum that is visible by the human eyes between 380nm to 495nm (right next to the harmful UV light and we all know how harmful UV light is to our skin and eyes). Due to the shorter wavelength, it is considered to be higher in energy that scatters more easily as compared to the other visible light rays(4).
The sun gives off white light but the sky appears to be blue. That is because when light rays (white light) strike air and water molecules in the atmosphere, the short-wavelength, high-energy light rays on the blue end of the visible light spectrum scatter more easily than other visible light rays(5). The higher degree of scattering of these rays is what makes the sky look blue even though if we fly up to space it is pitch dark.
Blue light is everywhere. In fact, the largest source of blue light is the Sun(6) and being outdoors during the day is where we get the most exposure to it. Contrary to UV light which is only emitted by the sun, blue light is emitted by every source of light(7). As long as you see light, there is blue light. Which means things like ceiling lamp, car headlights, and of course digital devices, phones, tablets, computers are also emitting blue light.
Even though the amount emitted is much lower than the sun , with the new age modern lifestyle that we are living, we are getting more and more exposed to blue light repetitively and at a shorter distance as we are spending more and more time on our smart devices or hand held devices(8). On top of this, the exposure to these artificial light source begins at increasingly younger ages. It also doesn’t help that more and more screens are being replaced with LED which emits a lot more blue light as compared to LCD or CRT screens(9).
As blue light is everywhere, everyone and anyone is exposed to blue light. What we are worried about is whether you are exposing yourself to too much blue light that you are increasing the risk to the effects of harmful blue light.
1. Contributor, J., 2020. What Is Electromagnetic Radiation?. [online] livescience.com. Available at: <https://www.livescience.com/38169-electromagnetism.html> [Accessed 22 September 2020].
2. Mountain View Optometry. 2020. THE FACTS ABOUT BLUE LIGHT. [online] Available at: <https://mountainviewoptometry.com/the-facts-about-blue-light/#:~:text=Light%20rays%20that%20have%20relatively,blue%2Dviolet%20or%20violet%20light.> [Accessed 22 September 2020].
3. Usgs.gov. 2020. Rainbows (Water And Light). [online] Available at: <https://www.usgs.gov/special-topic/water-science-school/science/rainbows-water-and-light?qt-science_center_objects=0#> [Accessed 22 September 2020].
4. Sliney DH, Freasier BC. Evaluation of optical radiation hazards. Applied Optics.
5. American, S., 2020. Why Is The Sky Blue?. [online] Scientific American. Available at: <https://www.scientificamerican.com/article/why-is-the-sky-blue/> [Accessed 22 September 2020].
6. Prevent Blindness. 2020. Blue Light And Your Eyes – Prevent Blindness. [online] Available at: <https://preventblindness.org/blue-light-and-your-eyes/#:~:text=The%20largest%20source%20of%20blue,CFL%20(compact%20fluorescent%20light)%20bulbs> [Accessed 22 September 2020].
7. All About Vision. 2020. How Blue Light Is Both Bad For You AND Good For You! (Huh?). [online] Available at: <https://www.allaboutvision.com/cvs/blue-light.htm> [Accessed 22 September 2020].
8. Pointsdevue.com. 2020. [online] Available at: <https://www.pointsdevue.com/sites/default/files/white_paper_blue_capture_a4_hd.pdf> [Accessed 22 September 2020].
9. Blue Light Exposed. 2020. Blue Light Exposed. [online] Available at: <http://www.bluelightexposed.com/#what-is-bue-light> [Accessed 22 September 2020].
Are all blue light harmful?
Not all blue light is harmful. As mentioned that blue light is from a wavelength of 380nm to 495nm. Studies have shown that blue light is made up of both the harmful blue-violet light (up to 455nm) and the beneficial blue-turquoise light (465-495nm). There are 2 types of blue light- harmful blue-violet light and beneficial blue-turquoise light.
The blue turquoise light is beneficial and important to us as it regulates our body clock and helps memory and cognitive function and elevates mood(10).
Blue light is important in regulating circadian rhythm — the body’s natural wakefulness and sleep cycle(11). Clinical reviews have suggested that exposure to blue light has a short term impact on melatonin suppression where its secretion is known to be related to the regulation of circadian rhythm and the sleep or wake cycle. Therefore, usage of digital devices such as reading a novel on a tablet computer or e-reader at bedtime may disrupt this cycle, potentially causing sleepless nights and daytime fatigue. One way to prevent this is to cut down on your usage of digital devices well before you go to bed(12). There are still studies going on about whether it can affect our retina or eye health. In Vivo, tests show that blue-violet light is more harmful to the outer retina. These tests used very high levels of blue-violet light- a lot more than what devices emit- but over a lifetime there are no definite answers. What we do know is that too much exposure to it can increase your risk of developing some form of eye strain and eye fatigue. We know is not possible, and besides it prevents us from receiving the goodness of the blue-turquoise light! As we have always been exposed to blue light since ancient times due to the sun, the concern now is that we are being OVER-exposed. The prolonged hours we spend in front of screens are causing our eyes to be affected by the glare. So of course then, some of the things you could do would be to cut down on your screen time to reduce the effects of the harmful blue-violet light. Again, we know this is a challenging task to complete!
10. Revieweducationgroup.com. 2020. The Lowdown On Blue Light: Good Vs. Bad, And Its Connection To AMD. [online] Available at: <https://www.revieweducationgroup.com/ce/the-lowdown-on-blue-light-good-vs-bad-and-its-connection-to-amd-109744> [Accessed 22 September 2020].
11. Cajochen, C. , Krauchi K., and Wirz‐Justice A.. (2003). Role of melatonin in the regulation of human circadian rhythms and sleep. J. Neuroendocrinol. 15:432–437.) [Accessed 22 September 2020].
12. Cajochen, C. , Frey S., Anders D., Spati J., Bues M., Pross A., et al. (2011). Evening exposure to a light‐emitting diodes (LED)‐backlit computer screen affects circadian physiology and cognitive performance. J. Appl. Physiol. 110:1432–1438.) and (Chang, A. M. , Aeschbach D., Duffy J. F., and Czeisler C. A.. (2015). Evening use of light‐emitting eReaders negatively affects sleep, circadian timing, and next‐morning alertness. Proc. Natl. Acad. Sci. U S A 112:1232–1237. [Accessed 22 September 2020].
The latest innovation from Essilor, Crizal Blue UV Capture lens.
Besides cutting down on screen time we highly advise to have additional protection for your eyes by wearing a pair of lens that cuts out some of the harmful blue light that is causing eyestrains and glare to help relief some of the symptoms and side effects that you are experiencing, so that you can continue with your daily life undisrupted.
The Crizal Blue UV Capture has the latest lens innovation in absorbing at least 20% of the harmful blue-violet light while still allowing the beneficial blue-turquoise light to pass through. On top of that, it provides a 100% of protection from UV light to give you optimal vision and protection both indoors and outdoors. (13) The night mode on phones, reduces the amount of blue light by having the light turn yellowish. It may be able to help reduce some form of glare as the light softens and is less harsh(14). However, it is unable to control whether the blue light filtered is just the harmful blue-violet light and that the beneficial blue-turquoise light still passes through. By having the night mode on your phones, it only protects you from a single particular source of blue light but does not protect you from the rest like your computer or even the lights in your room.
Finally, with the extensive amount of time we are spending exposed to blue light, there is no harm to have added protection with the blue light protection lenses even while using your phones in night mode. The more protection we get the merrier right!
13. Points de Vue | International Review of Ophthalmic Optics. 2020. Blue UV Capture™ : A New “In-The-Mass” Absorption Solution Against UV & Blue-Violet Light In An Optimal Clear Lens. [online] Available at: <https://www.pointsdevue.com/white-paper/blue-uv-capturetm-new-mass-absorption-solution-against-uv-blue-violet-light-optimal> [Accessed 22 September 2020].
14. American Academy of Ophthalmology. 2020. Should You Use Night Mode To Reduce Blue Light?. [online] Available at: <https://www.aao.org/eye-health/tips-prevention/should-you-use-night-mode-to-reduce-blue-light> [Accessed 22 September 2020].
What is the difference between Crizal Blue UV Capture lens and the normal optical lens in the market?
Most normal optical lens in the market do not have the function of protecting or filtering harmful blue-violet light from your eyes. Of course in the recent years, we are seeing more blue light protection lenses in the market due to the lifestyle demands of the user. As compared to regular prescription lenses, the Crizal (15). Before the invention of Crizal Blue UV Capture, the market consists of mainly 2 types of blue light protection lenses those that has a coating on top of the lenses that reflects blue light that gives off a very obvious bluish reflection off the lenses, and those that absorbs blue light that passes through which tend to leave behind a rather yellowish tint. Both lenses has aesthetic issues which is the main complaint that we have been hearing from our customers.
Which is why the Crizal Blue UV Capture has 3 main benefits: Besides the protection from harmful blue light, it also provides a 100% UV protection and has an e-SPF of 35 which basically means that it protects the eye from UV 35 times better than without any lens.(16) Finally, it ensures clarity on top, providing a solution to the disruptive bluish reflection of lenses or yellowish outlook that has been deterring people from getting a pair to protect their eyes with.
15. Points de Vue | International Review of Ophthalmic Optics. 2020. Blue UV Capture™ : A New “In-The-Mass” Absorption Solution Against UV & Blue-Violet Light In An Optimal Clear Lens. [online] Available at: <https://www.pointsdevue.com/white-paper/blue-uv-capturetm-new-mass-absorption-solution-against-uv-blue-violet-light-optimal> [Accessed 22 September 2020].
16. Points de Vue | International Review of Ophthalmic Optics. 2020. Blue UV Capture™ : A New “In-The-Mass” Absorption Solution Against UV & Blue-Violet Light In An Optimal Clear Lens. [online] Available at: <https://www.pointsdevue.com/white-paper/blue-uv-capturetm-new-mass-absorption-solution-against-uv-blue-violet-light-optimal> [Accessed 22 September 2020].
Is blocking blue light benefits everyone?
I think we have established the effects of harmful blue violet light, so yes, blocking blue light is good for everyone due to our lifestyle of constantly being glued to our phones and computers. However, as clear as we go, we cannot run away from physics and the principle of complementary colours. If an object absorbs a colour, it will appear as its complementary colour(17). Naturally, when it comes to a blue-light protection lens, it filters out blue. As blue and yellow are complementary colours, the absorber which stops Blue-Violet light gives the lens a yellow residual colour. For Essilor’s Crizal Blue UV Capture, we input a specific complementary colour absorber to neutralise the yellow residual colour. Despite having a very low residual tint which will not affect most people in their daily lives, the Crizal Blue UV Capture may unavoidably still be unacceptable for people like graphic designers or even dentists who are very particular with colour. As such, it will be good to have two pairs of glasses, one for the normal correction for work, and the other for their leisure where they have no need to be sensitive to colour and yet still be able protect their eyes from excessive exposure to blue light. So they may switch between the 2 glasses to get the required vision and protection they require!
According to a global research in 2019, people do not choose one device over another – they are multi-device owners, having an average of more than three different devices for various use(18). Today, 3 in 4 people suffer from visual fatigue linked to the daily use of smartphones, tablets, and computers(19). And with this pandemic, we are witnessing an exponential acceleration in digital adoption. Spending a whole day on video calls became a norm. More senior folks that didn’t know anything about online shopping and moving to online banking. People even do yoga lessons online and this change is here to stay. They have overcome the initial inertia of going digital and are unlikely to revert to old habits. In fact, Digital devices surround us 24/7.
With that, Blue UV Capture lenses are recommended for everyone. However, it is still advisable to book an appointment with your optometrist to have a comprehensive eye examination to find out more on whether you are suitable for the Crizal Blue UV Capture lenses. We do not consider it a coating as a coating is something that is applied to the top layer of the lens. The Crizal Blue UV Capture is a feature within the lens itself that can also come available with the other Essilor technologies. In fact, we have included the Blue UV Capture lens feature as a default offering in most of our lenses like the Varilux lenses and Eyezen lenses from Essilor.
17. Points de Vue | International Review of Ophthalmic Optics. 2020. Blue UV Capture™ : A New “In-The-Mass” Absorption Solution Against UV & Blue-Violet Light In An Optimal Clear Lens. [online] Available at: <https://www.pointsdevue.com/white-paper/blue-uv-capturetm-new-mass-absorption-solution-against-uv-blue-violet-light-optimal> [Accessed 22 September 2020].
18. Globalwebindex.com. 2020. [online] Available at: <https://www.globalwebindex.com/hubfs/Downloads/2019%20Q1%20Social%20Flagship%20Report.pdf> [Accessed 22 September 2020].
19. Sun-sentinel.com. 2020. Sun Sentinel – We Are Currently Unavailable In Your Region. [online] Available at: <https://www.sun-sentinel.com/health/sfl-more-than-73-percent-of-young-adults-suffer-from-digital-eye-strain-20160112-story.html> [Accessed 22 September 2020].