Do you know why the sky is blue? The typical answer is because the sky reflects the sea, but that’s actually incorrect. The sky is blue because of blue light, the same light coming from your LEDs, flat screen TVs, and smartphones. It’s both within nature and technology, making it present practically everywhere.
You may have caught a glimpse somewhere that blue light can cause negative health effects, especially to one’s eyes. But before you go there, try to see the bigger picture and learn the facts surrounding blue light:
1. Blue light was present long before fluorescent lights and digital devices were invented
It’s not just man-made. In fact, sunlight is the main source of blue light. However, that doesn’t mean sunlight is blue (neither is it yellow); sunlight by origin is white light. It’s a combination of colored light rays consisting of red, orange, yellow, green, and blue.
2. It’s responsible for the sky’s hue
In the light spectrum, blue light has the shortest wavelength and has the highest energy rate. Due to its shorter wavelength, it travels faster than other light colors and is easily scattered in the atmosphere. This is why you perceive the sky as blue because it’s the light color you see the most.
3. The sun has more blue light than the most powerful electronic devices
The sun is a natural source of blue light. Other sources of artificial blue light come from electronic devices such as smartphones, laptops, computers, LED lights and the like.
Despite that, the blue light emitted from electronic devices is relatively small versus the amount of blue light from the sun. That doesn’t cancel out risks from gadgets, though. It only means that you should also be wary of your eyes’ exposure to the sun.
4. Blue light affects your circadian rhythm
Blue light also regulates your circadian rhythm –the body’s natural wake and sleep cycle. Blue light signals your body to be awake during the daytime and reinforces a normal sleep cycle.
It’s important to note that exposure to blue light during bed time, or any light for that matter, is also not good. From the brightness of your screens to the dimmest glow of your night lamps, Stephen Lockley, a Harvard sleep researcher, notes that these are enough to cause lack of quality sleep. Unhealthy sleeping habits can increase risks of depression, diabetes and cardiovascular problems.
5. Your eyes block UV rays better than blue light
Even when you’re not wearing sunglasses, the UV radiation that reaches your retina is less than one percent. Blue light however, passes through the cornea and lens, all the way up to your retina where it can damage light-sensitive cells.
The important factor here is frequency. Exposure may not cause significant damage right away, but it may cause cumulative damage over long periods of time. Damage to the retina can cause eye problems such as macular degeneration and even vision loss.
Overexposure to blue light can also lead to digital eye strain. To filter blue light, use computer glasses, screen filters or anti-reflective lenses. It’s a good idea to lessen screen time, too. Make it a practice to give your eyes a break every 20 minutes to keep them well rested.
Blue light shouldn’t be taken lightly.
It looks like there’s no escaping blue light and it’s constantly surrounding everyone. You’re more exposed to it than ever before and perhaps even more than your eyes can handle.
While it’s true that studies are ongoing to fully understand its nature and effects, it’s best to be one step ahead to ensure the health of your eyes. Do this by educating yourself of the harmful effects of blue light and by practicing precautionary measures to protect your eyes.
- Heiting, Gary. (2017 November). Blue Light: It’s both Bad and Good for You. Retrieved from https://www.allaboutvision.com/cvs/blue-light.htm
- Blue Light and Your Eyes. (2016, July 18). Retrieved from https://www.preventblindness.org/blue-light-and-your-eyes
- Tello, Veronica. (2020, February 23). 7 Health Benefits of Blue Light Therapy + Side Effects. Retrieved from https://selfhacked.com/blog/blue-light-therapy-benefits/
- Blue Light Has a Dark Side. (2012 May). Retrieved from https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
- Yanoga, Fatoumata. (2019, June 13). Does Blue Light from Electronic Devices Damage Our Eyes? Retrieved from https://wexnermedical.osu.edu/blog/blue-light-and-vision