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While modern, energy-efficient LCD screens are better for the environment and our pocket than traditional CRT screens, they are not good for our eyes or our general health.

How much time each day do you spend staring at a computer monitor, tablet or smartphone?
                       
While modern, energy-efficient LCD screens are better for the environment and our pocket than traditional CRT screens, they are not good for our eyes or our general health.
                       
It’s ironic that we use sunblock and wear UV resistant sunglasses to protect our bodies and eyes from UV rays, but we do little to protect ourselves from the harmful effects of blue light that we are exposed to everyday.

The American Optometric Association (AOA) estimates that the average person spends 7 hours a day looking at a screen and 50-90 percent of computer users suffer from Digital Eye Strain.

The American Optometric Association (AOA) estimates that the average person spends 7 hours a day looking at a screen and 50-90 percent of computer users suffer from Digital Eye Strain. [1] The Vision Council notes that the situation is getting worse, with each generation using screens more than the last. [2]
                       
The aim of this article is to provide you with all the information you need to understand blue light and it’s harmful effect on health and to present you with the best available options for treatment and prevention.

 

What is Blue Light?

White light or ordinary daylight is made up of all the colors in the light spectrum. Each color has its own wavelength and the colors at the top of the spectrum have the shortest wavelengths and the most energy.

Natural blue light is part of the balanced spectrum of white light from the sun and this can have beneficial effects. Artificial blue light from screens and other LED lights, however, has a harmful effect on our health at any time of day.

Blue light, used in modern monitors, laptops, smartphones and tablets, is at the very top of the light spectrum along with UV light. It is energy-efficient which makes it more economical and less harmful to the environment than traditional incandescent light.
                       
Blue light has some positive effects on our bodies as it is necessary to “set our clocks.” [3] Exposure to blue light during the day regulates our sleep-wake cycle and can also help you to feel more alert. When exposed to the natural blue light in morning sunlight, the body will produce melatonin earlier in the evening, which is the hormone that triggers sleep. [4]
                       
All blue light is not equal, however. Natural blue light is part of the balanced spectrum of white light from the sun and this can have beneficial effects. Artificial blue light from screens and other LED lights, however, has a harmful effect on our health at any time of day. [5]

 

What is Digital Eye Strain (DES)?

Digital Eye Strain (also called Computer Vision Syndrome) is caused by a number of factors that are a result of people spending too much time staring at a computer screen, laptop, tablet or smartphone.
                       
You are more likely to suffer from DES if you have an existing problem such as farsightedness or astigmatism, problems focusing or coordinating your eyes and especially if you should wear glasses but don’t. People who suffer from problems associated with aging such as presbyopia are also more likely to get DES.

 

What are the symptoms of Digital Eye Strain (DES)?

The major symptoms of Digital Eye Strain (DES): eye strain, headaches, blurred vision, dry eyes and neck and shoulder pain

Digital Eye Strain isn’t one illness, it’s a group of vision-related problems and has a variety of symptoms. Some people are more prone to DES than others, some experience certain symptoms more than others.
                       
According to the American Optometric Association (AOA), the major symptoms of DES are

  • Eyestrain
  • Headaches
  • Blurred vision
  • Dry eyes
  • Neck and shoulder pain [6]

 

How is Digital Eye Strain diagnosed?

Regular eye checks are important for everyone, particularly people who use screens for prolonged periods every day. During your eye test, your optometrist will not only check your vision but also the general health of your eyes.
                       
According to the AOA, an eye-exam should include:

  • A discussion about your medical history and lifestyle to see if there are any other contributing factors to the symptoms of DES
  • Visual Acuity Measurements to see if your vision has been affected by eyestrain
  • A refraction to see if a prescription is needed to correct issues such as nearsightedness, farsightedness, or astigmatism
  • A test to see how the eyes focus and work together [7]
  • Your optometrist will be able to advise you about prescription glasses, Computer Vision Syndrome Glasses and if the muscles in the eyes aren’t working together as they should, vision therapy.

 

What causes Digital Eye Strain (DES)?

The causes of Digital Eye Strain fall into two categories: eye-related and physical.

 

Eye-related causes of Digital Eye Strain: blue light and glare

Modern screens use LED technology which is better for the environment and more economical because it is energy efficient. Unfortunately, LED screens emit blue light, which is damaging to the eyes and has other negative health effects.
                               
Studies have shown that blue light can cause damage to our retinas. A study in 2004 showed that short-wavelength blue light can cause macular degeneration, a disorder that used to be associated with age. [8]
                               
Subsequent studies have shown that blue light can penetrate the eye all the way back to the retina and can, therefore, damage it by causing the development of a toxic molecule called N-retinylidene-N-retinylethanolamine (A2E) that damages the cells. [9 and 10]
                           
Glare is also a contributory factor to eye strain. Glare is caused by light reflecting off shiny surfaces, and flickering or strobe lights which cause stress to our eyes.

 

Other negative effects of blue-light on our health

As well as having a detrimental effect on eye-health, blue light can also disrupt our sleep patterns and cause damage to our cells.
                       
According to research, 90 percent of Americans use a screen before bedtime. [11]
                       
Using your phone late at night, watching a movie, working late on a computer or even putting a night light in your child’s bedroom [12] can suppress the production of melatonin.
                       
A recent study that compared the effects of reading print books with e-readers at night found the e-reader group had a harder time getting to get to sleep, less time in REM sleep and felt less alert the next morning. [13]
                       
Melatonin has also been shown to have anti-oncogenic properties. In other words, it can help prevent cancer.
                       
The cells in our body are programmed to use melatonin as a signal that it’s time to rest and regenerate. Suppression of melatonin levels through exposure to blue light disrupts this process and can, therefore, speed the development of tumors and cause resistance to the cancer drug Tamoxifen. [14]
                       
In addition, photoreceptor cells in the retina have the highest concentration of docosahexaenoic acid (DHA) commonly known as fish oil. DHA is vital for vision, lowers blood pressure and facilitates the release of adenosine triphosphate (ATP) which provides energy for the cells. [15]

There are increasingly alarming studies being published about the dangers of blue light. Exposure to blue light caused irreversible retinal damage (blindness) in old flies. [16] Recently, another study found that blue light doubles a man’s risk of prostate cancer and increases a woman’s risk of breast cancer by 1.5 fold. [17]
                       
The negative effects of blue light on health, therefore, must not be underestimated.

 

Physical causes of Digital Eye Syndrome

DES is also caused by the eye muscles being overworked. As you read you move your eye along a line of text and then flick back to the start repeatedly. While you’re using a screen you are focusing and refocusing all the time. You alter your vision to look at images on the screen, or at written materials on your desk.
                       
Our eyes are at rest when they are looking at an object 20 feet away. Focusing for prolonged periods at a monitor or phone which is much closer causes the fragile ciliary muscles in your eyes to get tired.

Focusing for prolonged periods at a monitor or phone which is much closer causes the fragile ciliary muscles in your eyes to get tired.

In addition, staring at screens makes our eyes forget to blink which causes dryness. Bad posture as we hunch over our screens causes neck, back and shoulder pain.

In addition, staring at screens makes our eyes forget to blink which causes dryness. Bad posture as we hunch over our screens causes neck, back and shoulder pain.

As we get older all these factors get worse as the lenses in our eyes become more flexible and less able to refocus.

 

Treatment for DES

In today’s world where we are so dependent on our computers and phones, what can we do to prevent or reduce the effects of Digital Eye Strain?
                       
In addition to taking regular eye tests, these are some of the measures you can take.

 

20-20-20 Rule

In order to rest your eyes, the American Optometric Association recommend the 20-20-20 rule. Every 20 minutes stop looking at your screen and focus instead on an object 20 feet away for 20 seconds. [18] This allows the muscles in your eyes to rest, as it is the natural focus point for your eyes.

 

Reading Glasses

If you are supposed to wear prescription glasses do so, because if you don’t, your eyes will have to work harder and are more likely to get strained.

If you are supposed to wear prescription glasses do so, because if you don’t, your eyes will have to work harder and are more likely to get strained.
                       
It is important, however, that you make your optometrist aware of your screen use. The prescription you are given might not be correct for use with computers and smartphones as the viewing distance is different.
                       
In addition, normal prescription glasses will not protect your eyes from blue light. You might need Computer Vision Syndrome Glasses with lenses that are designed for computer use.
                       
If you normally wear contact lenses, consider switching to glasses when working at your computer as contact lenses tend to make your eyes dry, also a contributing factor to eyestrain.

 

Protective Eyewear

In addition, normal prescription glasses will not protect your eyes from blue light. You might need Computer Vision Syndrome Glasses with lenses that are designed for computer use.

The most effective way to protect your eyes from the harmful effects of blue light is to wear Computer Vision Syndrome Glasses. Even if you don’t wear glasses normally, you might benefit from wearing protective eyewear when you are at your computer as they are specially engineered to filter blue light and reduce glare.
                       
There are different sorts of Computer Vision Syndrome Glasses. Traditionally they had yellow-tinted lenses, which were effective in filtering blue light but were not aesthetically pleasing or pleasant to wear as they distorted color perception so everything looked yellow. In addition, we need exposure to some blue light during the daytime to regulate our sleep/wake cycle.
                       
Some glasses designed for computer use have an anti-blue coating. They look better than yellow-tinted lenses, as they’re clear, helping you avoid the “Riff Raff” look. Unfortunately, glasses with protective coating only block 20-30 percent of harmful blue light, and the coating can wear off over time.
                       
The most effective type of Computer Vision Syndrome Glasses have lenses that incorporate blue blocking material right in the lens rather than as a coating on the outside. These glasses filter out 50 percent of harmful blue light and the blocking material can’t chip or wear away. The lenses are also clear so you can wear them all day safe in the knowledge they look good. As they allow in some blue light they are also healthier for your sleep/wake cycle.

The most effective way to protect your eyes from the harmful effects of blue light is to wear Computer Vision Syndrome Glasses.

Some Computer Vision Syndrome Glasses also magnify which can reduce the stress on the ciliary muscle.

 

Eye Drops

The effects of dry eyes caused by reduced blink rate can be mitigated by the use of eye drops or artificial tears.

[Rohto Eye Moisturizer]

 

Proper Workstation/Ergonomics

Adjusting your workstation can help prevent Digital Eye Strain.

Adjusting your workstation can help prevent Digital Eye Strain. Here are some suggestions for improving the ergonomics of your desk.
                       
Reduce glare - Glare can be a big problem in offices, as light reflects off light-painted walls and shiny surfaces such as desks and flooring. Reduce glare by using an anti-glare screen or by using blinds or curtains to diffuse sunlight.
                       
Update your screen - The old style CRT (Cathode Ray Tube) screens flicker which is tiring for your eyes. Modern flat-panel LCD screens cause less strain and often have an anti- reflective surface. Screens with a higher-resolution are easier on the eyes.
                       
Minimize repetitive neck movement - Make sure you aren’t overworking your neck by looking up from something on your desk such as a notebook to your monitor frequently. Use a stand next to your monitor to hold your papers. You should be able to look from your reference materials to the screen without moving your head.
                       
Optimize your chair and desk height - It’s very important your chair and desk are at the correct height because bad posture can lead to eyestrain. Standing desks are good for posture. Chairs should be padded and conform to the body. Your feet should be flat on the floor. If you have arms on your chair they should be adjusted so you can use them to rest. You should not rest your wrists on the keyboard as you type.
                       
Monitor distance - Your monitor should be 20 - 28 inches from your eyes and the center of the screen should be 15-20 degrees (4-5 inches) below your eye line. [19]

 

Monitor settings

Make sure the display brightness on your monitor is similar to your surroundings, and that the text size is easy to read. It’s much easier for your eyes to read black text on a white background than any other color combination. Remember, your eyes have to work harder to focus on text on a screen than on a written page as letters aren’t so distinct. Reduce the amount of blue light in the color settings on your monitor.

 

Apps

Apps such as F.lux and Night Shift can filter blue light from your monitor, mobile phone and tablet by changing it to orange light at night.

Apps such as F.lux and Night Shift can filter blue light from your monitor, mobile phone and tablet by changing it to orange light at night.
                       
While this might be more comfortable for the eyes, even if you use the app your screen will still emit high-energy light. Apps do not change the LEDs that produce the blue light and it will, therefore, still enter your eyes and potentially damage them.

 

Ambient Lighting

Use curtains and blinds to reduce the effect of sunlight, and lamps that give out ambient lighting.

You might think bright screens in a dark environment are the worst thing for your eyes. In fact, using screens in an environment that is too bright is much more common and more likely to cause eyestrain.
                       
Make sure you aren’t sitting in a brightly lit area such as in full sun, or under harsh fluorescent lights. Use curtains and blinds to reduce the effect of sunlight, and lamps that give out ambient lighting.

 

FAQs

Are protective glasses more effective than apps such as F.lux and Apple Night Shift?

Computer Vision Syndrome Glasses are far more effective than apps such as F.lux and Apple Night Shift because they filter blue light and reduce glare. The apps do not change the LEDs on your screen that produce the harmful blue light, so this will still enter your eyes and can potentially damage them.
                       
Computer Vision Syndrome Glasses, on the other hand, filter harmful blue light so less penetrates your eyes. The most effective type of protective glasses incorporate blue blocking material into the lenses rather than as a coating. These glasses block 50 percent of harmful blue light, as opposed to coated glasses that block 20-30 percent. They also look better as they remain clear all day rather than turning blue as they absorb the blue light and are healthier for our sleep-wake cycle as they allow some blue light to penetrate.

 

Do glasses have to be tinted to be effective?

Computer Vision Syndrome Glasses do not have to be tinted to be effective. Today we incorporate a blue light blocking material into lenses that does not affect their color, but still reduces the amount of blue light that enters your eye and, therefore, protects your retina.
                       
Tinted glasses are not as practical as glasses that incorporate blue blocking material into the lenses as they make everything look yellow. They also don’t look as good as clear lenses and aren’t as healthy as we need some blue light during the day to regulate our sleep-wake cycle.

 

Final words

We are dependent on our screens for work, for communication and for entertainment, but prolonged use isn’t good for our health.
                       
Using screens for long periods can strain your eyes and make any existing problems you have with your vision seem worse. Prolonged exposure to blue light also disrupts sleep patterns and may have a harmful effect on cells.
                       
By taking precautions such as wearing Computer Vision Syndrome Glasses, observing the 20-20-20 rule and optimizing the ergonomics of our workstations, we can avoid Digital Eye Strain and even reduce the harmful effects of blue light on our health.


[1] Aoa.org. (2018). Computer Vision Syndrome. [online] Available at: https://www.aoa.org/ patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome [Accessed 18 Apr. 2018].


[2] Thevisioncouncil.org. (2018). Digital Eye Strain | The Vision Council. [online] Available at: https://www.thevisioncouncil.org/content/digital-eye-strain [Accessed 18 Apr. 2018].
                       
[3] David M. Berson, “Phototransduction in ganglion-cell photoreceptors,” European Journal of Physiology 454, no. 5 (2007): 849-855)


[4] M. Nathaniel Mead, “Benefits of Sunlight: A Bright Spot for Human
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[5] Jasonlauritzen.com. (2018). What You Need to Know About Blue Light and Health. [online] Available at: https://www.jasonlauritzen.com/what-you-need-to-know-about-blue-light-and-health [Accessed 18 Apr. 2018].


[6] Aoa.org. (2018). Computer Vision Syndrome. [online] Available at: https://www.aoa.org/ patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome [Accessed 18 Apr. 2018].
                       
[7] Aoa.org. (2018). Computer Vision Syndrome. [online] Available at: https://www.aoa.org/ patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome [Accessed 18 Apr. 2018].


[8] Karbownik M, Garcia J, Lewinski A, Reiter R. Carcinogen-induced, free radical- mediated reduction in microsomal membrane fluidity: reversal by indole-3-propionic acid. J. Bioenerg. Biomembr. 2001;33:73–8
                       
[9] Dillon J, Zheng L, Merriam JC, Gaillard ER. Transmission of light to the aging human retina: possible implications for age related macular degeneration. Exp Eye Res. 2004 Dec;79(6):753-9


[10] Arnault E, Barrau C, Nanteau C, et al. Phototoxic action spectrum on a retinal pigment epithelium model of age-related macular degeneration exposed to sunlight normalized conditions. PLoS ONE. 2013;8(8):1-12
                       
[11] Anne-Marie Chang et al, “Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness,” PNAS 112, no. 4 (2015): 1232-1237

 

[12] Joshua J. Gooley et al, “Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans,” The Journal of Clinical Endocrinology and Metabolism 96, no. 3 (2011): E463-E472.)
                       
[13] Lissoni P, Barni S, Ardizzoia A et al. A randomized study with the pineal hormone melatonin versus supportive care alone in patients with brain metastases due to solid neoplasms. Cancer. 1994;(73):699–701.


[14] Dauchy R, Xiang S, Mao L, et al. Circadian and melatonin disruption by exposure to light at night drives intrinsic resistance to tamoxifen therapy in breast cancer. Cancer Research. 2014 Aug 1;74(15) Retrieved from cancerres.aacrjournals.org on April 19, 2015.

 

[15] Jasonlauritzen.com. (2018). What You Need to Know About Blue Light and Health. [online] Available at: https://www.jasonlauritzen.com/what-you-need-to-know-about-blue-light-and-health/ [Accessed 18 Apr. 2018].


[16] Chen X, H Hall et al. Cytochrome b5 protects photoreceptors from light stress-induced lipid peroxidation and retinal degeneration. npj Aging and Mechanisms of Disease 3 (2017):2056-3973.


[17] Garcia-Saenz A et al. Evaluating the Association between Artificial Light-at-Night Exposure and Breast and Prostate Cancer Risk in Spain (MCC-Spain Study). Environ Health Perspect. 2018;126(4).


[18] Aoa.org. (2018). Computer Vision Syndrome. [online] Available at: https:// www.aoa.org/patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome [Accessed 18 Apr. 2018].


[19] Aoa.org. (2018). Computer Vision Syndrome. [online] Available at: https:// www.aoa.org/patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome [Accessed 18 Apr. 2018].

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