You may have heard the term “blue light” tossed around the workplace, at school, or in friendly conversation. Blue light, also known as high-energy visible (HEV) light, is a form of light in the visible spectrum. We are exposed to it every day, through sunlight, artificial light, and technological devices. The most natural state of light, the light radiating from the sun, is comprised of different colors (from red to blue), all which yield variant quantities of energy. The spectrum of light emitted by the sun is qualified as white light, or what we know as sunlight. A part of this light spectrum, blue light, between 380 and 500 nanometers, holds the focus of many technology users today. Computer screens, smartphones, and other devices emit blue light. 

So, why is blue light a hot topic? Though the quantity of blue light emitted from technological devices is nowhere near the amount created by the sun, prolonged use of these “blue light devices” may have an impact on your vision and overall health. Many parts of the eye, including the cornea and lens, are structured to block harmful rays like ultraviolet rays. Currently, scientists are aware that eyes’ overexposure to ultraviolet rays, light categorized between 100-380 nanometers, causes increased risk of eye diseases like cataracts and cancer. 

Blue light, on the other hand, is not known to cause these specific diseases, as it is not as extreme on the light spectrum. However, blue light still poses significant concerns for avid technology users. Blue light reaches the retina of the eye, as the eye is not effective at blocking blue light rays. This means blue light penetrates your retina regularly, and too much exposure can damage the light-sensitive cells in the retina, causing issues which resemble macular degeneration. In addition, looking at a computer or other device screen for a long period of time, causing prolonged exposure to blue light, may strain your eyes, resulting in a condition called “digital eye strain.” 

Constant use of technology also affects the body’s circadian rhythm. The body’s circadian rhythm is a sleep and wake cycle affected by different variables, including outside factors of lightness and darkness. When you expose your eyes to blue light late at night, you may have trouble falling asleep, as your body believes it is still “light” or time to be awake. With this in mind, doctors recommend limiting technology usage before bed, even restricting usage at least two hours prior to your normal bedtime. 

The real question is: is blue light really implementing your health? Not quite. Research has shown that blue light is essential for good health due to its ability to boost energy, increase cognitive function, improve memory, and elevate mood. Blue light therapy is even used to treat seasonal affective disorder- a seasonal-change related depression. However, since blue light is an essential circadian rhythm regulator, it is important to maintain a healthy blue light cycle. Until further studies are released, it seems blue light is okay in moderation. If you are exposed to technology regularly throughout the day, give your eyes a break by implementing the 20-20-20 rule. This rule outlines, after 20 minutes of viewing blue light, take a 20 second break and look at an object at least 20 feet away. For those who would like to take extra preventative measures, blue light filters are offered for installation on various devices and blue light protective eyewear is available without a prescription.