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Quick question; what is the last thing that you look at before heading to bed or when you wake up? If you’re like most of us, then the answer revolves around your smartphone—which is like an extra appendage in the modern lifestyle. Whether it’s scheduling our calendars, communicating, leisure, or working, we are always staring at one screen or another.
While these devices are convenient, they also notoriously expose you to blue light. What’s concerning is that several sources link this blue light to eye problems. Owing to the risk of blue light to eye health care and the proliferation of the blue-light-emitting devices, it’s important that you understand the relation between the two factors—and this is the purpose of this article.
First Things First; Understanding Blue Light
You probably know that the rainbow has 7 colours—red, orange, yellow, green, blue, indigo and violet. What you may not know is that each of these colours in the visible spectrum has different energy levels and wavelengths. Blue-hued rays have the most energy and shortest wavelength of the bunch—while red hues are the vice versa.
In addition to the sun (which is the main source of blue light) other sources include computer monitors, smartphones, flat-screen TVs, LED lights, and fluorescent bulbs. According to an article by Forbes, blue light from sunlight is beneficial to our circadian rhythms (wake-sleep cycles), mood, and attention. The problem is that our eyes were not designed to be excessively exposed to blue light past sundown.
Our Eye Aren’t Good at Blocking Blue Light
According to Dr Ajith Karunarathne from the University of Toledo, “We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it.” This means that a significant amount of blue light emitted by your devices finds its way to the retina. The question that follows is; how does this unfiltered short-wave and high-energy blue light affect the retina?
The Impact of Blue Light on Eye Health
The retina is a layer of specialized photosensitive cells deep in our eyeball—which is mandated with the noble role of converting light into signals that are interpretable by the brain. If this layer is damaged for any number of reasons, it may lead to age-related macular degeneration—a condition that often leads to blindness.
According to an animal study published in the Journal of Photochemistry and Photobiology, high-intensity blue light (400 nm, 420 nm, and 435.8 nm) damages photosensitive retinal cells in mice. While this is not conclusive evidence on the harmful effects of blue light on human eye health, it nonetheless raises questions.
Staring closely at blue-light-emitting devices also increases the risk of digital eye strain. Think about; how long do you ogle at an exciting Instagram video or that suspenseful show on Netflix that always has you on your toes? Coupling this lack of blinking with concerns over the impact of blue light on our retina, it’s easy to see why managing the time we spend on our devices is crucial.
As stated in an article appearing in The Ohio State University Wexner Medical Center, there’s growing concern over the long-term effects of exposure to blue light. More specifically, blue is the closest colour on the visible spectrum to ultraviolet on the invisible spectrum—and this close association is a cause for concern.
Keeping the Blue at Bay
- Limit screen time: The American Academy of Pediatrics recommends limiting your child’s screen time before bed. Adults should also heed to this piece of advice—and if not, at least dim your screens and take frequent breaks.
- Follow the 20-20-20 rule: The American Optometric Association advises you to look at something that’s 20 feet away for 20 seconds every 20 minutes. This reduces the risk of digital eye strain and dry eyes.
- Make use of lubricating eye drops: Did you know that you halve your blinking rate (from 12 to 6 blinks per minutes) by staring at a screen? This leads to dry, inflamed eyes—hence necessitating the use of lubricating eye drops.
- Consider blue light filters: The idea is to make use of accessories such as specialized screen coatings or mobile filter apps to reduce the amount of blue light that finds its way to your eyes at night.
