-The EYE Digest-
Feeling Blue - Blue Light and Its Effect on the Eyes and Body
In modern times, screens have become a ubiquitous and often necessary means of production, education, and entertainment. Computer monitors, TVs, tablets, and phones constantly surround us. In the year 2017, you would be hard pressed to find an individual, young or old, that does not spend some time per day on a screen. Heck, you’re reading this article right now on a screen (unless if you printed it out, then kudos to you!).
A hot button topic that has been thrown around with computer screen usage is blue light. You may have heard that blue light can cause eyestrain, or even affect the sleep cycle. But what exactly is blue light and how can it affect our eyes and overall health? Let’s take a deeper look.
What is Blue Light?
Light can be broken down grossly into two types: visible and invisible light. Invisible light includes infrared, radio, ultraviolet, X-ray, and gamma ray. Visible light includes all light emitted with wavelengths that range from 290 nm to 700 nm. In this range of wavelengths, the color spectrum is contained. Blue light specifically, encompasses the range of 380 nm – 500 nm. These wavelengths are shorter than the “warmer” colors such as red and orange.
Where is Blue Light found?
Blue light is found nearly everywhere. The sun is constantly emitting blue light, so if we are outside we are constantly being exposed to blue light. The indoor environment presents blue light through tablets, computer screens and fluorescent lights.
Does Blue Light cause eyestrain? And if so, how?
Blue light is a big culprit in causing eyestrain. Blue light is of higher energy than other colors of light due to its low wavelength. This causes blue light to scatter easily and thus makes it more difficult for the natural lens inside the eye to focus on blue light.
When looking at a computer screen light of all colors is emitted. When the eye tries to focus on an image on the screen it must focus while trying to filter out the scattered blue light, which essentially creates visual noise. When the eye is subject to doing this for long periods of time, it becomes strained from constant focusing and refocusing.
Can Blue Light affect sleep/Circadian Rhythm?
Yes! Blue light does have an affect on the sleep cycle and can disrupt the Circadian Rhythm. A Harvard research study found that blue light can substantially alter melatonin (a necessary chemical in the sleep cycle) production in the body. This is due in part to blue light’s natural tendency to stimulate and awaken the body.
Further conclusions from this have shown that blue light is affecting us more than ever before. Why? Device usage, including tablets and phones, before bed, is at an all time high. This blue light blitz before bed can have a drastic effect on both falling asleep and sleep quality.
How about Blue Light and Macular Degeneration?
A few years ago, a link between blue light exposure and macular degeneration was established. However, the topic is highly controversial and there is very little scientific evidence supporting blue light being a causative factor of macular degeneration.
How can we stop Blue Light?
There are a variety of ways that we can stop or limit blue light exposure in our daily activities. The first and most obvious is to avoid blue light altogether. This means spending less time on phones and screens.
The second method is to employ blue light filter screens on our devices and monitors. These can substantially reduce blue light exposure. Additionally, devices like the iPhone have a settings option called Nightshift, which reduces the amount of blue light emitted by the phone.
Finally, one can use blue blocking lenses (sometimes called computer lenses). These lenses, which may be clear or have a slight yellow tint, filter out blue light, enabling the eyes to work with substantially less strain on screens and devices.
-Dr. Aaron Neufeld
Dr. Aaron Neufeld is the Chief Optometrist at Los Altos Optometric Group and primary author and editor of The EYE Digest.
Contact him with questions or ideas for future articles at (650) 948-3700 or firstname.lastname@example.org