What Is Blue Light?
Blue light’s name comes from its color. It can be present even when people perceive the color of light as white. They have a wavelength between 400 and 450 nanometers, and it carries more energy per photon than other colors.
Blue wavelengths are beneficial during daylight hours because they boost attention, reaction times, and mood, but they are the most disruptive at night.
This type of light has always been around. It is naturally found in sunlight, but technology has made our contact with it more frequent. Nowadays, people spend at least a few hours a day in front of computers, television, tablets, and smartphones, all of which have screens that are made of light-emitting diodes (LED) and emit shorter (and therefore brighter) waves of blue light. Energy-efficient light bulbs made of LED is another increasingly common source of blue light.
Effects on the Eye
Some kinds of light can cause permanent damage to the eyes. Ultraviolet rays, for instance, can lead to diseases such as cataracts and increase the risk of eye cancer. The small amount of blue light coming from device screens, however, has not been shown to cause harm to our eyes. This doesn’t mean the devices we use every day are completely harmless.
Eye Strain
The problem is not the blue light itself, but how people use the devices. Staring at a computer or cellphone screen for many hours a day and keeping it too close to the face can often cause computer vision syndrome, also known as digital eye strain.
People with eye strain may have different symptoms. The most common ones are classified into internal ocular symptoms (strain and ache), external ocular symptoms (dryness, irritation, burning), visual symptoms (blurred or double vision), and musculoskeletal symptoms (neck and shoulder pain).
When we stare at a screen for too long, we tend to blink less frequently, which can result in dry eyes. Many eye symptoms caused by computer use are usually temporary, and will lessen after you stop using the computer.
Sleep Disruption
Checking your phone in bed seems harmless, but it can affect how well you sleep. Blue light can influence the circadian rhythm, which is responsible for letting your body know when to sleep and wake up. Light of any kind, even dim light, can suppress the secretion of melatonin, a hormone that influences circadian rhythms, but blue light at night does so more powerfully.
Light at night is the reason why most people don’t get enough sleep at night. Short sleep is associated with an increased risk for depression, diabetes, and cardiovascular problems.
Research has also shown that blue light is linked to cancer, diabetes, heart disease, and obesity.
Do Blue Light Glasses Work?
Blue lights glasses are coated with a yellow-tinted material that filters blue light from digital screens. Manufacturers recommend their use while looking at gadgets. It is not necessary to wear them while doing activities that don’t involve looking at screens. Unlike normal glasses, people don’t need a prescription to buy a pair.
Although blue light glasses don’t cause any harm, there is no scientific evidence showing that wearing these glasses offer any benefits the manufacturers advertise. While some users say that they feel better wearing blue light glasses while working on the computer, there are not enough studies that prove they improve visual performance or sleep quality, alleviate eye fatigue, or conserve macular health.
Furthermore, the American Academy of Ophthalmology states that the blue lights don’t cause diseases or permanent damages, and there are other ways to prevent symptoms.
Other Tips
Most of us can’t avoid computers and phones most of the day, but it is possible to do little things that will minimize blue light’s negative impact on our eye health and sleep:
Keep your computer or laptop at a reasonable distance: One of the most common mistakes when using a computer is sitting too close to it. Ideally, you want to keep the computer screen 25 inches away (or the distance of one arm). Also position your screen so that you are gazing slightly downwardTake breaks: Take regular breaks using the 20-20-20 rule: every 20 minutes, shift your eyes to look at an object at least 20 feet away for at least 20 secondsUse artificial tears: When your eyes feel dry, use artificial tears to refresh your eyesUse a matte screen filter: For those who want to reduce the screen glare, a matte screen filter is an easy solutionDon’t look at your phone before sleep: Avoid looking at your phone at least two to three hours before bed. You can also set the devices on night modeUse dim red lights for night lights: Red light is less likely to affect your circadian rhythmExpose yourself to lots of bright light during the day: This will boost your ability to sleep at night, as well as your mood and alertness during daylight
A Word From Verywell
No evidence so far shows that blue light glasses are effective at minimizing blue light’s impact on eye health and sleep, but there are other ways you can keep blue light from causing symptoms and affecting your daily life. The issues caused by devices can be easily prevented or controlled in simple ways, but persistent symptoms should never be ignored. People should have their eyes checked out by an ophthalmologist regularly. This will help to avoid future problems and identify underlying diseases early.
