If you were to calculate how much time you spend each day looking at your smartphone, computer, tablet, and TV, chances are it'd be more hours than not. And if you've ever gotten a headache from staring at your various screens all day, or noticed your eyes are always super dry, you've experienced one of the most 21st-century health problems, "digital eye strain."
Digital eye strain is more than a reality; it is a public health priority in the United States. This is the warning published by The Vision Council*, which has just released its latest survey on this issue: Hindsight is 20/20/20: Protect Your Eyes from Digital Devices 
. The document is based on an analysis of 9,749 questionnaires completed by a representative sample of adult U.S. residents. It aims to determine the broad outlines of behavioral changes concerning digital displays, be they smartphones, tablets, computers, laptops, or other electronic devices, such as game consoles. This state of play confirms the trend that has emerged in recent years: “From the moment people get up until the time they go to bed again – including when they are eating, exercising and reading – they are using one digital device after another and thus exposing themselves to risks related to prolonged exposure to light emitted by screens,” sums up Mike Daley, chief executive officer of the Vision Council. In concrete terms, more than 95% of American adults spend at least two hours a day in front of a screen and almost three out of ten spend over nine hours. Even though people working on computers are the most concerned by a potential “overdose”, the study stresses that one child out of four is exposed to screens over three hours a day. These constantly increasing figures can be explained by both new societal patterns (i.e. a decrease in physical activity, an increase in passive consumption and paperless contacts, etc.) and options made possible through innovation. “Digital technologies offer ever-increasing options and opportunities to simplify consumers’ daily lives. This growing trend is not likely to be reversed any time soon. Nor are the related ophthalmic problems,” Daley predicts.
Adults spend half of their waking hours—61 hours, or two and a half days, per week—looking at digital screens. The main effect of prolonged exposure (greater than two hours per day) to light emitted by screens is digital eye strain. Described as a passing discomfort, it manifests itself in different forms with symptoms such as red, dry or irritated eyes, blurred vision, pain in the neck, shoulders or back, headache, etc. “Weblink 18 times a minute on average. However, staring at a screen for an extended period can result in less frequent blinking that could dry or even irritate the eyes 
”, Erin Hildreth reminds us. according to a recent report
by vision insurance provider VSP. And that can do a number on the state of your body from the neck up, Gary J. Morgan, O.D., a VSP optometrist and expert on blue light, macular degeneration, and the impacts of technology on vision and health, tells SELF.
"In the short term, discomfort from digital eye strain can lead to symptoms of headaches, dry eyes, blurred vision, and neck, shoulder, and back pain," he explains. In the long term, the picture is even dimmer. Experts say there's growing evidence that clocking more screen time might lead to irreversible deterioration of the retina and may even change the shape of our eyeballs.
Here's what you need to know. (And yes, we recognize the irony that you have to read this on a screen, but we think it’s worth it.)
The blue light emitted from electronic devices causes eye strain, which can lead to headaches, and even back and neck pain.
You probably know blue light from its melanin-suppressing effects—any sleep expert will tell you to quit the electronics
as early in the evening as you can if you want a shot at deep, uninterrupted sleep. But the glow from your iPhone can also irritate your eyes. "The problem is that blue light wavelengths are short and are out of focus in front of the retina, the image-capturing lining found in the back of our eye," Morgan explains. If you think about the eye as a camera, the retina is the film (or in more modern terms, the image sensor). "And although our eyes are constantly trying to focus this out-of-focus blue light, the focusing muscles of the eye physically can't do it. So this constant focusing effort results in eyes that feel tired, dry, burn, or tear up."
These tired, strained muscles affect everything around them, causing headaches
. Your body may also tense up when you're trying so hard to focus. "Much like when we tense up when lifting something heavy, we might get neck, shoulder, and back pain."
Too much screen time may lead to poorer vision and permanent eye damage (but the jury's out on what “too much” really means).
"While it is difficult to pinpoint how many hours per day of screen use is cause for concern," research shows that cumulative exposure to blue light over a person's lifetime contributes to the development of age-related macular degeneration (AMD), Morgan says. "AMD is a progressive deterioration of the center of the retina known as the macula, responsible for our sharpest vision." It's the leading cause of blindness of people over 55 in the developed world. Thanks to all our fancy-schmancy devices and high-efficiency, blue-light-blasting bulbs like LED, we're exposed to a significant amount of blue light daily. "As our visual environment and behavior have changed so drastically, the problem we face is that there are no long-term human studies to tell us how much exposure may lead to the development of the disease," Morgan says.
Meanwhile, myopia, or nearsightedness
, has been rising at an alarming rate, and experts believe it's related to how much more screen time we log. "When spending extended time looking up close, the eye has to focus harder to see the image," Morgan explains. "This constant effort can lead to elongation of the eyeball, so the light from closely viewed objects is more effectively focused at the back of the eye. However, this leaves distance objects out of focus, as this elongated eyeball is now considered myopic, or nearsighted." Myopia can put you at risk for other eye problems, like glaucoma and retinal detachment. Best-case scenario, you’ll be spending your FSA money on glasses for driving.
Advances in ophthalmic optics have already made possible a wide range of options for lenses capable of reducing glare and filtering out blue light. These two indispensable options to optimize visual comfort while using digital displays should encourage opticians to add them to prescriptions to more closely meet their clients’ needs. “Many manufacturers also offer multifocal lenses for people who need to relieve eye strain and correct both near and far vision,” Dora Adamopoulos added. The medical advisor feels that “the optical/ophthalmic industry must continue to engage in research and development for new products, but also educate the community of vision care professionals and the general public. We have to explain to consumers that they do not have to live with discomfort or pain while using digital devices. Custom glasses, with or without corrective lenses, can alleviate or prevent short-term symptoms and protect against long-term damage.” It is more important than ever to disseminate this message since scientific advances are increasingly confirming the link between digital displays, eye strain, age-related eye diseases, and the importance of prevention and protection. “The new digital era is more stressful on our eyes and we must all adapt accordingly, professionals and users alike. The optical/ophthalmic industry has already identified the major issues raised by digital devices and during the last several years, we have witnessed a boom in innovation capable of reducing disorders related to the light emitted by screens. These products and technologies do much more than protect our eyes: they improve the quality and precision of our vision,” Mike Daley concluded.