Blue light has the shortest wavelength and highest energy of any color of light on the visible spectrum. Exposure to blue light is needed for good health because it elevates mood, assists cognitive functions, boosts alertness, and regulates our circadian rhythm, however, too much exposure to blue light can have a damaging effect on vision. Humans are being exposed to more blue light than ever before due to modern technological innovations, and the effects of this increased exposure are only beginning to be understood.
Sources of blue light exposure:
- The sun
The sun is the strongest and most common source of blue light to most people. Humans have evolved to use the blue light coming from the sun throughout the day to regulate circadian rhythm by sending hormonal signals that tell us when to be alert and when we need to sleep.
- Fluorescent and LED light bulbs
Fluorescent light bulbs are becoming much more common due to environmental efficiency. Fluorescent light bulbs emit much more blue light than traditional incandescent and halogen light bulbs.
- Computers, phones, tablets, and TVs
Long-term exposure to the blue light emitted from the screens of our technology is becoming a greater concern to eye health practitioners due to the fact that people tend to be very close in proximity to their screens and spend a long time looking at them. According to a recent study, children absorb more blue light from their technological devices than adults do.
Effects of blue light exposure:
- Digital eyestrain
Digital eyestrain is a relatively recent phenomenon, attributed to the massively increased amount of screentime the average person is exposed to on a daily basis. Digital eyestrain can lead to dry, sore, or irritated eyes, as well as difficulty focusing. Digital eyestrain is a major concern for office workers who spend the majority of their time working in front of a computer screen.
- Retinal damage
Recent studies suggest that increased exposure to blue light can cause cellular damage in the retina. This damage is a major concern because damaged retinal cells can cause serious vision problems like macular degeneration, which can lead to permanent loss of vision.
Ways to mitigate blue light exposure:
- Decrease screen time
The best way to mitigate unnatural increased exposure to blue light is to simply decrease the amount of time we spend looking at our screens and to take frequent breaks when spending a lot of time looking at screens. A good rule of thumb that we suggest is to spend 20 seconds looking at an object 20 feet away for every 20 minutes that we spend looking at our screens.
- Screen filters
Many vendors offer screen filters to eliminate some blue light emitted from screens on computers, phones, tablets, and televisions. These filters generally have adhesive on the back and are simply stuck onto the surface of a screen. Manufacturers of technological devices are also increasingly building features into their software that will digitally eliminate some of the blue light coming from screens. Apple’s “Night Shift” feature is an example of a blue light filter built directly into a device’s software.
- Blue light filtering lenses
Glasses lens manufacturers now offer lens coatings and materials that filter out blue light. Lenscrafters offers Blue IQ and Blue IQ Clear lenses on prescription glasses, and there are also non-prescription blue light filtering glasses available. Blue light filtering lenses generally have a yellow tint, however Blue IQ Clear lenses filter out blue light with barely any visible tint on the surface of the lens.
- Intraocular lens surgery
During cataract surgery, the patient’s cloudy lens will be replaced with a synthetic intraocular lens that protects the patient’s eye from most blue light exposure.