It’s almost like every gift bestowed by the modern world comes at a price. Clean homes have been linked to disease outbreaks. The poor ventilation of energy-efficient buildings increases the chance of contracting COVID-19. And the blue light emitted by everything from smartphones to LED lights may be responsible for all manner of eye issues––from nearsightedness in children to cataracts in seniors. So why is blue light so damaging? And are there glasses that can actually protect us?
Feeling Blue Over Blue Light
In nature, blue light is part of the visible spectrum––the portion of the electromagnetic spectrum you can see. This form of electromagnetic radiation can be subdivided into seven colors. Think of a rainbow. This happens when light passes through matter––depending on its wavelength, light is either absorbed or reflected. The colors that are reflected are the visible portion of a rainbow––ultraviolet would be to the left, while infrared would be on the right of the invisible part of the spectrum. Most people see light in wavelengths between 380 to 700 nanometers (nm). Hotter objects have different colors than cooler ones. This is why we perceive our sun as yellow. Our closest star has a surface temperature around 5,500°C. A couple thousand degrees cooler, and it would look red. If it was twice as hot, it would appear blue. Picture a blowtorch shifting from red to blue or the flame on a gas stove. For our eyes, this blue is the most damaging. Studies suggest that short-wave blue light with wavelengths between 415 nm and 455 nm can harm your eyes. This high-energy blue light passes through the cornea and lens to the retina. It has been linked to dry eyes, cataracts, and age-related macular degeneration. Blue light also alters our body’s natural chemistry by stimulating adrenocortical hormone production––which wakes us up, while suppressing melatonin––which puts us to sleep. Because of the hormonal imbalance caused by staring at blue light, our natural sleep pattern can be interrupted or abbreviated.
A cataract happens when the lens of our eyes or the surrounding membrane becomes cloudy. It’s the leading cause of blindness across the world. Although the connection between sun exposure and cataracts has been known for decades, the link between the impairment and blue light is far more recent. Exposure to blue light can also lead to the development of cataracts. Examining white light-emitting diodes (LED) with different correlated color temperatures, one study determined that they could cause significant damage to the lens. On the other end of the age spectrum, an earlier study concluded that children who spent the most time staring at a computer screen had higher incidences of nearsightedness. Television watching, on the other hand, did not seem to contribute to the condition.
Unfortunately, blue light is almost unavoidable. Indeed, an earlier French study also concluded that LED lights can damage our eyes, yet in the European Union traditional incandescent light bulbs were banned. LEDs are a primary source of domestic light in the EU. The United States also moved toward banning incandescents in the name of energy efficiency, but that restriction has recently been lifted. Few people are restricting their screen time, however. Before the adoption of artificial light, most humans “got up with the chickens”––awakening with the sunrise and going to sleep soon after sunset. Today, even night owls find their sleep disrupted by smartphone notifications or tablet binging of TV shows. Eyeglasses designed to filter out blue light promise to improve sleep and undo the damage.
Using male teens as subjects, one study determined blue blocking glasses are very effective at filtering out the damaging light. Despite hours of screen time, the subjects had an easier time falling asleep. Like most products in our modern age, there are numerous pairs of blue-blocking glasses available. Finding the right pair for you will require some research. Sellers should offer clear information about the technological specifications of their products. Since they range in price from a few dollars to over $100, there is a range of quality as well. One of the hardest things to size properly, eyeglasses are best purchased in person. Of course, if you already wear prescription glasses, you will want to talk to your doctor.
Buying and wearing eyeglasses may not be practical or desirable for everyone. There are other solutions. Consider replacing LED lights in your home––especially in a bedside lamp you use for reading. Despite bans, incandescent bulbs are widely sold online. Turn off–and away from–your electronics at least one hour before going to bed. Vitamin A along with antioxidants like vitamins C and E have proven beneficial for eye health. So are the carotenoid antioxidants lutein and zeaxanthin along with omega-3 and omega-6 fatty acids. Oral supplements are fine, but drops placed in the eye are ideal. Regardless of which option you choose, just being aware of what blue light does to your eyes and looking at how to minimize the damage is an important step.
Written by John Bankston
References
- How can airborne transmission of COVID-19 indoors be minimized?
- Tour of the Electromagnetic Spectrum.
- Electromagnetic Radiation
- Research progress about the effect and prevention of blue light on eyes
- Effects of white light‐emitting diode (LED ) light exposure with different Correlated Color Temperatures (CCT s) on human lens epithelial cells in culture
- Reading, writing, working on a computer or watching television, and myopia
- Light-emitting diodes (LED) for domestic lighting: any risks for the eye?
- Blue blocker glasses as a countermeasure for alerting effects of evening light-emitting diode screen exposure in male teenagers
