People are spending a majority of waking hours staring at a computer screen, tablet, or cell phone. Even children are using digital devices more often, as a lot of schoolwork has transitioned to an online format. Blue light emitted by electronic devices can contribute to computer vision syndrome, or digital eye strain. Thankfully, there are lenses available to help alleviate the symptoms associated with hours of computer use.
Blue Light Physics
The sun produces both visible and invisible light rays. Different wavelengths and colored light rays contain unique amounts of energy. Blue light is a form of visible light in the middle of the energy spectrum, although it is the closest wavelength of visible light to the invisible light wavelengths, such as ultraviolet (UV) light. UV light and other types of invisible light have more energy than visible light. The body needs UV light in moderation to help produce vitamin D, but as we all know, UV light can cause damage to the skin and eyes if exposed for prolonged periods. Therefore, blue light is also called high-energy visible (HEV) light due to its proximity to the higher energy invisible wavelengths.
Sources of Blue Light
Blue light is present in all forms of visible light. The most prevalent sources are the sun, digital device displays (computers, tablets, smartphones, televisions, etc.), and fluorescent lighting.
Disadvantages of Blue Light
Blue light from a digital device tends to decrease the clarity and contrast of the content on the screen. This defocus can exacerbate computer vision syndrome, or “digital eye strain”, as the eyes have to work harder to see clearly when looking at a screen for an extended time. Symptoms of computer vision syndrome include eye fatigue, headaches, fluctuating or blurred vision, and dry eyes. The symptoms are typically worse while actively on the device, however, they may persist even after stopping.
Not all blue light is bad. Some blue light is responsible for helping memory, increasing alertness, raising mood, and regulating the circadian rhythm. The circadian rhythm is the body’s natural response of knowing when it is time to sleep versus being awake and alert. Too much blue light before bedtime can actually disrupt the circadian rhythm and release of melatonin, making it difficult to fall asleep. Moderating the quantity of blue light and balancing time on handheld devices can be challenging, but blue-blocking lenses can help decrease exposure for those using electronics all day.
Protection Against Blue Light
Blue light protection is present in glasses that contain a blue light filter. At Weber Vision Care, we prefer ophthalmic-grade filters that are part of the lens material itself, rather than a coating on the lens. When the blue blocking technology is within quality lens material, the lens does not have a yellow or orange colored tint like other over-the-counter lenses on the market. The “good” blue-turquoise light passes through the lens, while the harmful blue-violet light is absorbed and filtered by the lens.
Anti-reflective or anti-glare treatments are also very beneficial in addition to the blue light protection. This helps further decrease glare, while increasing contrast. Many patients notice the biggest improvement in eye strain, fatigue, and headaches by wearing glasses that have a combination of anti-reflective and blue-blocking treatments.
Obviously, the best way to decrease blue light exposure is to decrease the amount of time looking at a digital device, however, this might not be a viable option for everyone. Following the 20-20-20 Rule gives a mini-break for the eye muscles and focusing system to relax. For every 20 minutes on a device, look at least 20 feet away, for 20 seconds. Another way to limit blue light is to avoid looking at bright screens within 2 hours of going to sleep. Some newer editions of electronic devices have a sleep or night mode that switches the screen to a yellow or amber tint.
If you spend any extended amount of time on a computer, tablet, or smartphone – blue light protection is for you! More and more schools are going online for the upcoming year, and your children will benefit from the same blue light protection. Even if you or your children do not typically wear glasses for reading, you are still an excellent candidate for blue-blocking lenses for electronic device usage. Call our office to schedule an appointment with one of our friendly and knowledgeable opticians!
