May 30—In the age of technology, blue light exposure has become a part of daily life for almost everyone.
Blue light is the type of light emitted from LED's in electronic devices, such as televisions, smartphones, tablets and laptops. Not all blue light is bad, as the main source of it is the sun.
Sunlight contains visible and invisible ultraviolet light rays. Visible light rays come in different colors that have varying wavelengths and emit varying amounts of energy, according to the Ohio State University Wexner Medical Center. Warmer color light rays have relatively long wavelengths and contain less energy, while cooler colors with short wavelengths have more energy. Blue light fits in the latter, having shorter wavelengths and more energy.
While the sun's blue light exposure is larger than that of devices, the devices emit large amounts of the light, according to the Mayo Clinic, and are closer in proximity to one's eyes. Thus, it can potentially lead to harmful long-term effects.
Prevent Blindness, a national nonprofit, says that early research indicates that an overabundance of blue light can lead to digital eyestrain. Symptoms of this can include sore or irritated eyes, difficulty focusing or headaches.
Another negative effect of blue light can be on one's circadian rhythm, according to the American Academy of Ophthalmology. The Academy says that blue light is stimulating to the eyes and research has shown that exposure to the light can wake people up, suppress melatonin levels and phase-shift the biological clock.
In a clinical trial, researchers compared the biological effects of reading an electronic book on a light-emitting device with reading a printed book in the hours before bedtime. Participants reading the e-book took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock and reduced next-morning alertness than when reading a printed book.
Dr. Rahul Khurana, a spokesperson for the Academy, recommends that people try to limit their screen time in the two to three hours before going to bed.
Eye Care One, an optometry office with two Aiken locations, lists some ways to combat the negatives of blue light on its website. The company says these options include computer glasses, specialized lenses and protective coatings.
In addition to the preventative measures, Eye Care One also recommends the the 20/20/20 rule — after every 20 minutes of near tasks, people should look at something beyond 20 feet away for at least 20 seconds.