A growing number of us are glued to our smartphones day and night. It seems like some people simply can’t tear themselves away. If you fall into this category, your obsession with your phone could be doing serious damage to your eyes. The blue light from your screen may be causing much more than just eye strain. You might be at a high risk for macular degeneration and other severe vision problems.
Blue Light – The Basics
Without getting too deep in a lesson on optics, light travels in waves that emit energy. These waves have different lengths (wavelengths) and come in different strengths. The shorter the wavelength, the higher the amount of energy it emits. Wavelengths comprise what is known as the electromagnetic spectrum.
We can only see the visible portion of that spectrum, and we see it as colors. These include red, orange, green, yellow, violet, indigo, and blue, as well as various shades of these colors. Blue light produces a great deal of energy because it has a very short wavelength. As a matter of fact, it’s at the very end of the visible spectrum – located right next to invisible ultraviolet light.
You’ll find blue light everywhere – in fact, sunlight is the main source. The blue light rays from the sun make the sky look blue because when the wavelengths of the rays hit air molecules, that causes a scattering of blue light. But there are plenty of man-made sources as well, including LED lighting, flat-screen TVs, and computer and smartphone screens. LED technology helps to make a screen bright and clear, but it also emits extremely strong blue light waves. While the average smartphone screen, of course, emits only a fraction of blue light that comes from the sun, the amount is still significant.1
The reason that so many doctors are concerned about the potential dangers of blue light is that many of us spend an incredible amount of time looking at a blue light screen. And because blue light is packed with so much energy, that can result in a glare that can lead to eye strain and other issues.
An Unhealthy Nationwide Addiction
According to the Nielsen Company — an elite research firm — the average adult in the U.S. spends an average of nearly nine hours a day staring at some sort of technological device. Tablets, laptop computers, and desktop computers get their share of “eye time,” but smartphones make up the lion’s share.2
Research into the effect of blue light from smartphones suggests that staring at a phone all day can lead to severe consequences. The lens and cornea are unable to filter blue light, and as a result, it heads straight for the back of the eye. The eye does a very good job of blocking dangerous ultraviolet (UV) rays from reaching the retina (even if you’re not wearing sunglasses). Blue light? Not so much.
Blue Light and Macular Degeneration
Because blue light penetrates the retina, this can damage certain cells that are extremely sensitive to light. This could lead to retinal damage that results in macular degeneration, a condition that can lead to blindness.
Macular degeneration is, unfortunately, extremely common – in fact, it affects more than 10 million people in the U.S. Even worse, there’s no cure. It develops when the central portion of the retina, known as the macula, becomes damaged over time. The retina is the part of the eye that transmits images to the brain via the optic nerve. The macula helps to focus our vision, making it possible to do things such as recognize details in an object, read, recognize colors and faces, and drive.
If you liken the eye to a non-digital camera, then the macula is the most sensitive portion of the film that goes inside. When it works correctly, it’s able to collect extremely detailed images of an object and send them to the brain, which, in turn, interprets those images. However, when the cells that comprise the macula begin to break down, the images start becoming “fuzzy.”
People who have macular degeneration actually don’t notice any vision problems at first. As the disease progresses, however, vision may become blurred or wavy – eventually leading to a complete loss of central vision. When someone is diagnosed with an advanced form of macular degeneration, they are considered to be legally blind – even though the rest of the retina works fine and that person still has peripheral vision.
It’s unclear as to exactly why macular degeneration occurs, although certain contributing factors have been identified. For example, people over the age of 55 are at the highest risk, and smoking can double your chances of developing the condition. You’ll also be at a higher risk if a family member has macular degeneration. Hispanics and African-Americans suffer from the condition in smaller numbers than Caucasians.3
Other Vision Issues Associated with Blue Light
Another potential consequence of staring at a smartphone all day is digital eye strain, which is also referred to as “computer vision syndrome.” Digital eye strain symptoms include headaches, blurred vision, dry, tired eyes, and difficulty being able to focus.
Blue light isn’t all bad. It may actually help improve attention, brighten mood, and increase reaction times during the day. Doctors sometimes use a treatment known as light therapy to help people with a form of depression known as seasonal affective disorder (SAD). As the name implies, people with SAD tend to experience symptoms when seasons change – particularly from the beginning of fall through the end of winter. While white light is typically used in therapy, it contains a substantial amount of blue light rays.
However, blue light can be very disruptive to our circadian rhythms at night. In a nutshell, the circadian rhythm is our internal clock that tells us when we need to get up, when we need to be productive, and when we need to rest.
While it’s not clear as to exactly why blue light exposure at night is bad, there’s a growing body of evidence that it can lead to potentially serious problems. One study suggests a link between a disruption in the body’s circadian rhythms and the development of diabetes and obesity. Ten participants were placed on a schedule that gradually changed their circadian rhythms. According to the results, all of them experienced an increase in blood sugar that put them into the “pre-diabetic” classification. They also showed lower levels of leptin, which is a hormone that promotes a feeling of fullness after eating.4
In addition, studies indicate that blue light may inhibit the secretion of a hormone known as melatonin, which helps ensure that our body maintains a healthy rhythm.5 If you don’t have enough melatonin, that can make it very hard for you to get enough sleep – and when you don’t get enough sleep, you’ll be at a higher risk for a variety of health problems.6
Blue light has been shown to inhibit melatonin secretion much more than other types of light. Researchers conducted a study comparing how people were affected after nearly seven hours of exposure to blue light versus the same amount of exposure to green light. They found that not only did blue light suppress melatonin twice as much as green light, it also substantially altered the participants’ circadian rhythms.7
What Can You Do About It?
Since so many of us are joined at the hip to our smartphones, it probably won’t do a lot of good to suggest that you cut back on staring at your screen all day. But there are a few things that you can do in order to potentially reduce the risk of developing macular degeneration, or experiencing other health issues, due to blue light overload.
For example, if you just have to stare at a screen during most of your waking hours, try having a blue light filter installed. This will help protect you from digital eye strain and other issues – and it’s also very convenient. You can find filters for not only smartphones, but also computer screens and tablets. They reduce the amount of blue light that gets to your retina, and you won’t have to sacrifice the clarity of the display. There are even some filters that contain tempered glass to help protect your device from scratches.
Special computer glasses may also help to reduce exposure from technological devices – and you don’t need any sort of prescription to be able to wear them. But prescription lenses are also available. If you use bifocals, computer glasses provide you with a wider field of vision, so you can get a clear view of your entire screen. Just remember that these glasses are only made for objects that are no more than an arm’s length away. You won’t be able to use them for distance viewing – and you’ll definitely need to remember to take them off before driving anywhere.
Another important tip is to give your eyes a rest periodically if you’re in front of a screen all day. Try stepping away for about 20 seconds every 20 minutes and focusing on something that’s at least 20 feet away, such as a window or a piece of furniture. You could also set a reminder on your phone to take a break if need be.
And, although you might think it’s ridiculous to suggest that you should remember to blink more often, you’d be surprised at just how little we blink when we’re intensely focused on a screen. When we don’t blink enough, we’re not only more susceptible to digital eye strain, but also dryness, blurred vision, and even pain.
Other Ways to Avoid Blue Light Damage
If you are preparing to have cataract surgery, talk to your doctor about how much blue light your new intraocular lens will provide. You might also consider wearing glasses that contain a blue light filter if you plan on spending a lot of time in front of a computer or staring at a smartphone screen.
Other things you can do to avoid potential blue light damage include avoiding your smartphone or computer screen two or three hours before you go to bed, and using a dim red light for a night light instead of a blue one.
So, even though blue light has been linked to some serious vision problems, by taking the right precautions, you can go a long way toward minimizing any potential damage it may cause.
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