Being a student who primarily uses my laptop and tablet for school, I can spend copious hours a day staring at a screen. Time and again, we have been warned about how this heavy usage of mobile devices can affect our eyes — specifically, how blue light, the main source of light that most digital devices emit, can cause permanent damage. Some sources, however, have rebutted this argument, stating how the blue light from these devices is not harmful and won’t cause any damage to your eyes. 

So … what is the answer?

Blue light is part of the visible light spectrum rainbow within the electromagnetic spectrum. With its wavelength being around 400 to 450 nanometers, it has a much higher energy compared to other visible light colors, such as red and orange, on the opposite side of the spectrum. Although there are some exceptions, it can be generally stated that the higher the energy of radiation, the more dangerous and harmful it is. Blue light, therefore, is more likely than other colors to be more damaging to your body at high levels.

Does that mean blue light from mobile devices can damage your eyes and increase your likelihood of impaired vision?

Right now, the answer is no. Although blue light does have a relatively high energy level, David Ramsey of Harvard Health states “consumer electronics are not harmful to the retina because of the amount of light emitted.” Electronic devices do not produce a high enough intensity of blue light that would be considered damaging or degrading to your eyes. It was found that the most it can do to our eyes is cause them to feel sore or strained, of which there is little to no evidence of causing eventual eye damage. However, not much is known about the long term effects and what may result from intense, daily exposure of our eyes to mobile devices in the long run.

A blue light source that is sure to be harmful, however, is the sun. Sunlight, as we all know it, can be very dangerous for our eyes. Of course, if we stare at it as long as we do with our phones, we are bound to have some sort of eye damage. In fact, staring at the sun for even just a few seconds can cause dangerous rays to enter your retina and oxidize the tissues, destroying the eye’s rod and cone photoreceptors: neurons that allow your brain to interpret visual information.

Although blue light may not affect our eye health does not mean they do not affect other parts of our health. Long periods of exposure to blue light can disrupt your circadian rhythm or “body clock.” Blue light can make us alert and stimulated. This is caused by it having the ability to block the secretion of melatonin, a hormone used by our body to make us feel sleepy. When using digital devices just before we go to bed, it can make it difficult for us to actually fall asleep and get enough rest. This can result in having trouble focusing or learning the next day. In more dangerous cases, when you are repeatedly not getting a healthy amount of rest, chronic health issues are more likely to arise, such as heart disease, kidney disease and depression.

Nevertheless, there are still ways in which you can prevent the harmful effects of blue light. When going outside, sunglasses with high quality lenses will be able to protect your eyes from high levels of both visible light and ultraviolet rays. Computer glasses can also be used when spending a large amount of time on electronic devices to filter out blue light and prevent your eyes from feeling strained and to allow for a good night’s rest. Another solution is to either lower the brightness of your device or turn on the “Night Shift” mode in your settings for a more gentle light on the eyes.

Although it can be said as of now that the blue light from our phones is not destroying our eyes, there is not enough conclusive evidence for long term cases with high levels of daily exposure. As students who spend a majority of our time on these devices, it is important to be aware of how long you are on these devices and how they may affect you. In any case, it is always safe to limit our daily amount of screen time to prevent any possible harmful effects.