Smartphones can damage the eyes and cause disturbed sleep. Therefore, Natural Eye Care has issued safety guidelines for smartphones. We have summarized research on how smartphone misuse could contribute to the onset of serious eye diseases such as glaucoma and macular degeneration. Eye strain and discomfort from improper smartphone habits create unnecessary suffering. Night time smartphone use leads to poor sleep.
However, there is much you can do to prevent problems from smartphones. At the end of this article, you will find suggestions for how to use smartphones without damaging your eyes. For example, keeping the phone farther away from your face is better. Your phone has a built-in report about your usage. Additionally, you can teach loved ones habits that help preserve healthy vision.
Symptoms of Smartphone Eye Damage
The symptoms of smart phone damage are the same as the symptoms for Computer Vision Syndrome:
- eye strain
- eyes feel dry, itchy, or stinging
- blurred vision
- headache, neck, or shoulder pain
- seeing double
- trouble concentrating
Additionally, blue light emitted from screens can interfere with sleep. The sun provides blue light, telling our body to wake up. Blue light from screens in the evening keep us awake. The sleep hormone melatonin does not get produced in sufficient amounts, preventing us from falling asleep and getting sound sleep.
Excessive exposure to blue light over many years, from sources such as sunlight, computer screens, and smartphones, can contribute to or even cause eye diseases like as macular degeneration.
While these diseases mostly strike the elderly, a lifetime of bad vision habits causes cumulative damage. Eye disease prevention should be practiced at all ages.
Why Smartphones are Worse than Computer Screens
The screen technology in modern computer monitors and smartphones are similar. However, smartphones are portable, and the screens are much smaller. Therefore, we use smartphones differently, and these habits threaten our vision. These days people often use smartphones to do all their computer work in place of a desktop or notebook.
The main issue is the distance we hold smartphones away from the face and eyes. While a typical computer should be at least 20″ away from the face, a study found that subjects held smartphones an average of 11.5 inches away from the face. 3 The researchers asked youths aged 18-25 to read an extract of a novel on a smartphone for one hour. Researchers tested for eye fatigue before and after reading. The scientists measured how far away the students held their phones while reading. The distance varied throughout the reading period, between 8.6″ and 14.4″ away from their faces, getting increasingly close as time when on — and — closer than was found in previous research. The subjects reported a significant increase in symptoms of tired eyes, uncomfortable eyes, and blurred vision.
Smartphones provide convenient entertainment while a person is lounging in bed. People lying down tend to hold the phone very close to their face than when they sit up; between 3.9″ and 8.4″.4 Additionally, lying in bed is often associated with lights out. Looking at a smartphone screen with no ambient light causes excessive dilation of the pupils which allows even more blue light into the eye.
Hunching over a smartphone promotes poor posture, contributing to headaches, neck pain, and back pain.
Hazardous for Pedestrians
Highly portable, smartphones are a distraction for pedestrians. Walking while looking at a screen increases the chance of all types of accidents, including head and eye injuries. The danger is not just out in public; half of all injuries occur at home. 5 One study found that older people especially lose their balance and ability to navigate when dialing (looking at) their phones while walking.6 A meta-study concluded that texting while walking is especially dangerous, likely due to the mental load that language puts on the brain. 7 Honolulu has issued a “Distracted Walking Law” to help reduce injuries to pedestrians — especially seniors — using their smartphones.8
What the Research Shows About Smartphones
Smartphones are relatively new, becoming widespread in the late 2000’s. 9. Yet, they have significantly impacted our world. Scientific researchers are looking into their effects on human physiology.
- Young people who read a novel extract for 1 hour on a smartphone had increased blurring, discomfort of the eyes, and tired eyes. 10 In standard eye strain tests, before the experiment, their score was 3.56; after, it was 8.06 (p < 0.001). The closer they held the phone, the worse they scored.
- Holding a phone closely was associated with poorer sleep in a Japanese study of young adults. 11 The scientists measured the quality of sleep using several standard scales and questionnaires. The subjects either laid down or sat up to use the phone at bedtime. When the subjects laid down to use the phone, they held the phone closer. These subjects had significantly lower quality of sleep versus the others, including poorer sleep state and lower sleep efficiency. Also, they took more time to fall asleep and reported experiencing poor sleep.
- Smartphone screens are smaller and, by default, the type is also small. When users over-ride the character size, less material fits on the screen, and it may not format properly. A study of smartphones found that young people held the phones closer when the font was smaller. Conversely, older people held the phone further away (likely due to presbyopia, blurring of close-up objects after the age of 40). 12
- Circadian light is light which stimulates the human circadian system. This is light which suppresses melatonin. Performance qualities for circadian luminous efficacy of radiation (CER) and circadian illuminance (CIL) have been developed. Luminous efficacy means how well a light source produces light. Illuminance means how well the light illuminates what it is shining on.
A study examined three types of commercially available smartphone displays. All of them emitted too much light when using social messaging in the dark, exceeding the figures. Thus, they are likely to suppress melatonin production. Testing the screens in bright room at night would have an even worse impact on melatonin production. 13
- Incomplete blinking while reading was worse when looking at an electronic display compared to print media.14 Not fully closing the eye when one blinks causes dry eye, inflammation, redness, and more serious conditions.
- Tools are being developed to measure the extent of smartphone addiction.15 The tiny jump in dopamine from getting a text or other communique on a smartphone has an addictive quality.
How to Minimize Vision Damage from Smartphones
Safe smartphone use can help prevent eye injuries and disease.
- Set limits on the amount of time you spend on your smartphone. Your phone tracks how many times you unlock the phone and total time per day. Look in the settings or download an app that tracks usage.
- Don’t stare at the screen for more than 20 minutes. Stand up and look 20 feet away for 20 seconds. Put the phone away and take a short walk if possible.
- Remember to blink fully and frequently while on your phone.
- Download our free eye exercise ebook.
- Keep the screen as far away from your eyes as is comfortable. Don’t look at it close-up. If the content is hard to see, change the size of the content or wear glasses. Or, view the content on a larger computer or tablet screen.
- While watching videos, turn the phone on its side so the video fills the screen. Set the phone down on a phone holder. See picture below.
- Check your posture. Keep your back, neck and head aligned to prevent pain.
- While lying down, use a long arm mobile phone holder. Position the phone as far away from your face as possible. See picture above.
- Turn on a light when using a smartphone. Never use it in the dark. See our article about why light bulb choices matter.
- Turn down screen brightness in low lighting conditions.
- See if your phone has a built-in blue light filter setting. If not, download an app or use glasses that filter blue light. Turn it on in the evening.
- Don’t use screens 1 to 2 hours before bedtime. Blue light before bed interferes with sound sleep. Read a paper book or a Paperwhite Kindle. Talk, play acoustic instruments or games, or write in a journal.
- Monitor children closely and teach them screen safety. Install a family safety app to limit their usage. Turn the WIFI off and take away electronics at night to discourage nocturnal smartphone usage.
- Young people might feel invincible, but the effects of poor smartphone habits are cumulative. Nearly all young people in the USA own a smartphone (97-98%)16. However, only 65% of seniors age 65+ owned one in 2016. Talk to young adults about protecting their vision throughout life.
- Certain nutrients and vitamins help protect the eye from blue light damage, including lutein, zeaxanthin, and astaxanthin. Eat a diet rich in brightly-colored fruits and vegetables. See our nutrition guidelines and Vision Diet.
Smartphones fulfill important needs for communication, information, and connection. Use them safely to protect your vision.
- Possible association between heavy computer users & glaucomatous visual field abnormalities: a cross sectional study in Japanese workers, Journal of Epidemiology and Community Health 2004;58:1021-1027 Masayuki Tatemichi et.al. ↩
- Do blue light filters confer protection against age-related macular degeneration? by Margrain TH et. al. Progressive Retina Eye Research, September, 2004. ↩
- Viewing distance and eyestrain symptoms with prolonged viewing of smartphones. Long J et. al., Clinical and Experimental Optometry, March 2017. ↩
- Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology. Yoshimura M. et. al., Nature and Science of Sleep, March. 2017. ↩
- National Safety Council ↩
- The effect of cell phone use on postural balance and mobility in older compared to young adults. Laatar R. et. al., Physiology & Behavior, May, 2017. ↩
- A narrative review of texting as a visually-dependent cognitive-motor secondary task during locomotion. Krasovsky T. et. al., Gait & Posture, February, 2017. ↩
- “It’s Now Illegal To Text While Crossing The Street In Honolulu” by Miles Parks, National Public Radio, July 29, 2017. ↩
- Smartphone, Wikipedia ↩
- Viewing distance and eye strain symptoms with prolonged viewing of smartphones. Long J et. al., Clinical and Experimental Optometry, March 2017. ↩
- Op. cit. Yoshimura ↩
- Readability of characters on mobile phone liquid crystal displays. Hasegawa S et. al., International Journal of Occupational Safety & Ergonomics, 2008. ↩
- Analysis of circadian properties and healthy levels of blue light from smartphones at night. Oh J.H. et. al., Science Reports, June, 2015 ↩
- Blink Rate and Incomplete Blinks in Six Different Controlled Hard-Copy and Electronic Reading Conditions. Argilés M. et. al., Investigations in Ophthalmology and Visual Science, October, 2015 Oct. ↩
- Assessment of the accuracy of a new tool for the screening of smartphone addiction. Khoury JM, PLoS One, May, 2017. ↩
- Nielson’s Mobile Insights, March, 2016 ↩