For years our patients have asked us if blue light causes long term vision damage or other health effects related to its exposure. The reality is that we are exposed to many types of light on a daily basis even if we can’t see it; however, not all forms of light are harmful. Much like ultraviolet light, blue light can affect us even though we are not able to see it. Because this is a reoccurring question we receive, we want to dive into a few common questions: What is blue light? How does it affect our bodies and our eyes? What can I do to protect myself from blue light exposure? Let’s begin!
What Is Blue Light?
Blue light is a form of visible light that is present in the light spectrum between 380 and 500 nanometers (nm). While blue light is in fact blue, it can also be present in different colored light as well, including white light. For example, when you look at your computer or phone screen, though it seems to emit a white backlight, blue light is still very much present. Light rays with longer wavelengths tend to harbor less energy as the energy itself is spread “thinner”. Blue light has the shortest wavelength of visible light. Because of this, exposure to blue light results in exposure to more concentrated energy, which is why it is a concern.
Blue Light & Our Circadian Rhythm
Our biggest source of blue light is the sun, which is why many scientists are concerned that exposure of blue light from our electronics can disturb our body’s circadian rhythm, the natural process within our body that determines our sleep-wake cycle, by suppressing our natural melatonin secretion. Because there is quite a bit of evidence to support this theory, companies like Apple have created “Night Mode”. Night Mode lessens the amount of blue light emitted by our Apple electronics to lessen circadian rhythm confusion within our own bodies. Apple recommends utilizing Night Mode from 10 PM until 7 AM, though this feature allows you to customize your Night Mode schedule as you please.
Fun Fact: Blue light emitted by our sun is the reason we perceive the sky as blue!
How Might Blue Light Affect Our Eyes?
The truth is that our eyes are not structured to handle the energy emitted by blue light very well. While our eyes are great at blocking ultraviolet (UV) light, 100% of the blue light we are exposed to makes its way to our retina. Scientists and eye doctors alike are concerned that too much exposure to blue light may result in macular degeneration. Long story short, scientific evidence suggests that blue light kills our photoreceptor cells and these cells do not regenerate. The plus side is the vitamin E present in our eyes protects us from blue light damage to our photoreceptor cells. The bad news is that the amount of vitamin E present in our retina lessens with age, potentially causing blindness after many years of exposure to blue light.
How Can We Protect Ourselves From Blue Light?
As we mentioned above, Apple products come with Night Mode as a standard feature to protect us from blue light exposure. We would even go as far as to say you should be running Night Mode or an effective alternative on all of your electronic devices whenever possible. Another step you can take to limit your eyes’ exposure to blue light is to wear glasses and sunglasses with blue blocking technology. These lenses are designed with a spectrum control mechanism. These lenses can minimize blue light exposure to your retina by quite a bit, reducing eye strain and toxic damage blue light may cause. We recommend trying to find blue blocking lenses that reduce at least 95% of the blue light your eyes are exposed to. We are in very early stages of understanding how blue light affects our bodies and more specifically, our eyes. As we learn more, the likelihood of technology created to fight against blue light toxicity will also become more common. If you are concerned about the amount of blue light your eyes are absorbing, call us to schedule an eye exam today!