Helping your patients understand the effects of blue light exposure on their eyes
Most of your patients probably know how important it is to protect their eyes from the sun’s UV rays (and if they don’t, we recommend emphasizing this to them). But how many of them know that it’s also important to protect them from blue light?
While there is a lot of recent talk about the effects of blue light on our health (and our eyes), many people still don’t fully understand what it is.
To throw some light on the subject (excuse the pun), we decided to focus this post on presenting you with simplified information that you can give to your patients about blue light and its effects on their eyes.
What is blue light?
Sunlight is made up of a spectrum of light with red, orange, yellow, green, and blue light rays – some of which are visible and some of which are invisible. In this blog post, we’ll be focusing on the visible part of the spectrum. However, it’s important to note that exposure to the invisible part of the spectrum, especially UV rays from the sun, can also have a damaging effect on the eyes.
Without going into too much detail, the rays on the red end of the visible light spectrum have longer wavelengths and give off less energy, and those on the blue end of the spectrum have shorter wavelengths and give off more energy.
The portion of the visible light spectrum with the shortest wavelengths and the highest energy comprises approximately one-third of all visible light and is known as blue or high-energy visible (HEV) light.
While the subject is still being researched, what we currently know is that blue light has both positive and negative effects on health.
Let’s start with the good news… Not all blue light is bad! It turns out that some blue light exposure is actually good for our health. In fact, research shows that this light boosts our alertness, helps our memory and cognitive function, and even elevates our mood.
In addition, exposure to blue light during the daytime helps maintain a healthy circadian rhythm, which is our body’s natural wakefulness and sleep cycle (so think about what happens when we’re exposed to it at night, but we’ll get to that later).
In terms of eyesight, early studies are showing that children who are not exposed enough to sunlight (and blue light) are at a higher risk of developing myopia. So that was the good news. Now onto the concerns about blue light exposure – here’s what your patients need to know.
Important facts about blue light
1. Blue light is actually all around us. When outside, light travels from the sun and through the atmosphere. The shorter blue wavelengths collide with air molecules and cause blue light to disperse everywhere, making the sky look blue (on a clear day). We get most of our exposure to blue light from sunlight, but there are also many other man-made sources of blue light that include fluorescent and LED lighting, flat-screen televisions, computer display screens, smartphones, and other electronic devices. The amount of HEV light given off by these devices is much smaller than the amount emitted by the sun. However, because we spend so much time staring at these devices (studies suggest that 60% of people spend more than 6 hours a day looking at screens!) and we hold them quite close to our faces, there is concern about the long-term effects of this additional exposure to blue light.
2. The eye is much better at blocking out UV rays than it is at blocking out blue light. Our anterior eye structures (the cornea and lens) can effectively prevent most of the visible UV rays from reaching the light-sensitive retina at the back of our eyeballs (though it’s important to protect the eyes from both the sun’s UV rays and invisible infrared light). However, the cornea and lenses are less effective when it comes to blocking blue light, and almost all blue light passes through them and reaches the retina.
3. Blue light can cause digital eye strain. As blue light has the shortest, highest-energy wavelengths in the visible light spectrum, it scatters more easily than other visible light and causes flickering. This kind of flickering creates a glare that reduces the visual contrast of the images we see, and this unfocused digital “noise” can cause eyestrain, headaches, and physical and mental fatigue after long periods of exposure to electronic screens.
4. Too much blue light late at night can disrupt our sleep cycle. In contrast to the benefits of blue light exposure during the day, too much exposure to screens and indoor lighting at night may cause difficulty falling asleep, poor sleep quality, and fatigue the next day.
5. Too much blue light exposure may increase the risk of macular degeneration. Studies have shown that because blue light penetrates all the way to the retina, too much exposure to blue light can damage the light-sensitive cells in the retina. This can cause changes in the eye that are similar to those of macular degeneration, which may in turn lead to permanent vision loss.
More research is still required to determine exactly how much blue light is “too much blue light” for the retina, but there is definitely a growing concern about the amount of blue light we’re being exposed to from screens on a daily basis.
What can your patients do to protect their eyes from too much blue light exposure?
There are a number of measures your patients can take to protect their eyes from blue light exposure.
For example, they can reduce the brightness of their screens, use screen filters and apps that filter the blue light from screens without affecting visibility, and take frequent breaks from screens to give their eyes a rest (using the 20-20-20 rule – for every 20 minutes spent looking at a screen, they should look away at something 20 feet away for 20 seconds).
You can also help them protect their eyes from blue light by offering them Shamir Blue Sun™, Shamir Blue Zero™, and Shamir Glacier Blue Shield™ – our innovative and proven solutions that can be used separately or combined for the most comprehensive and effective protection against blue light exposure.