Eye Effects

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Updated 11/20/19- Scientific Articles follow the summary

Digital Screen Time: Dry Eye, Cataracts, Computer Vision Syndrome

It is well established that eye structures are harmed by exposure to solar UV radiation. Points De Vue 2017 That is why ophthalmologists and optometrists advise wearing UV protective sunglasses when outdoors. Newer research is now showing that there are a host of serious risks associated with exposure to digital screens, blue light and radiofrequency radiation from wireless devices. The American Academy of Ophthalmology is concerned that too much screen time is now affecting children’s vision, including myopia and dry eye symptoms.

eye-1173863_1920Eyes Are Vulnerable

The eyes are much more vulnerable as they have no outer protective layer. Studies demonstrate cumulative damage to the cornea and lens of the eye with long-term UV/sunlight exposure and now evidence is also pointing to non-ionizing radiation from wireless devices as causal agent for cataracts with a similar mechanism of oxidative damage.

Blue Light, Retinal Damage, Insomnia and Chronic Disease

Published data is also adding  LED blue light from screens and lighting as a true risk for retinal damage and circadian rhythm disruption with screen time as a risk for dry eye syndrome and computer vision syndrome along with melatonin reduction and sleep disorders from blue light exposure. Sleep disruption (or chronic insomnia) can have profound effects on our health and is associated with a host of chronic diseases, including cancer, obesity, high blood pressure, heart disease, poor memory, depression and anxiety, as well as poor learning performance. Melatonin, an important internal antioxidant, also protects eye structures from oxidative damage from a variety of sources.

Cataracts on the Rise

There is a continued rise in the prevalence and incidence of cataract surgery which is attributed to better access and diagnosis, without consideration of ubiquitous environmental causes, such as increased screen time with blue light exposure. With children, whose  systems are still developing and who are now exposed to screens at home and now mandated at school, there are even more serious concerns.



Computer Vision Syndrome and Dry Eye

Computer Vision Syndrome (CVS) is an increasingly recognized but an under-diagnosed syndrome resulting from prolonged screen time with video display terminals (computers, laptops, tablets, cell phones).  Symptoms include include headache, eyestrain, tired eyes, irritation, redness, blurred vision, and double vision. Dry eye symptoms often accompany CVS with reduced blinking rate and increased corneal exposure. There is evidence that atrophy of  the lubricating meibomian glands around the eyes are involved as well. Researchers warn that people spending more than 4 hours a day at the screen are at major risk to develop dry eye symptoms and computer vision syndrome.  It is estimated that 50 to 90 % of  students and those who use computers at work experience this. The American Academy of Ophthalmology has recommendations to reduce eye strain with the use of digital devices.

Eye Strain

Using cell phones and tablets at close distances to view movies or read for long periods causes eyestrain. A study by Long (2017),  Viewing distance and eyestrain symptoms with prolonged viewing of smartphones of young adults using a cell phone for 60 minute to read showed a significant increase in eye strain, with students reporting tired eyes, uncomfortable eyes and blurred vision. Another study by Antona (2018), Symptoms associated with reading from a smartphone in conditions of light and dark showed significant eyestrain from using a smartphone for prolonged periods versus a hardcopy, especially if the smartphone was used in the dark.

The 20-20-20 Vision Rule

Staring at screens from computers, cell phones, gaming, tablets and television for long periods of time can cause eye fatigue and computer vision syndrome with blurred vision tearing, and headaches. To reduce eye strain it is recommended to use the 20-20-20 rule: Every 20 Minutes look at something 20 feet away for 20 seconds. It is also recommended to:

  • Position your screen an arms length away from your eyes and at 20 degrees below eye level
  • Alternate from looking at your screen to looking at paperwork and your surroundings
  • Match the brightness of your screen with surroundings
  • Remember to blink. When we are not on the computer we blink 12 times a minute but when on the computer we blink only 5 times a minute
  • See a physician if you have symptoms of computer vision syndrome
  • Consider a low blue light computer shield or low blue light glasses from a reputable company that reduce blue light.


 China Bans Digital Screens in Classrooms to Prevent Eye Damage

Because of the growing evidence for the risk of eye damage from digital screens and concerns with myopia China has banned cell phones from classrooms. See China Bans Smart Phones in Schools . The Ministry of Education and the National Health Commission has banned the use of cell phones and tablets in classrooms in Shandong province and asked parents and teachers to:

  • Not rely on electronic devices for teaching and assignments and use written assignments
  • Limit children’s use of electronic screens not more than one hour a day and not exceed 15 minutes in a single session
  • Keep proper distance from eyes and screens
  • Have correct reading positions
  • Have sufficient backlighting


Retinal Oxidative Eye Damage and Blindness From Blue Light

Researchers from Sweden in 2006 reviewed  the pathogenesis of age-related macular degeneration. In their paper looking at light damage, Age-related maculopathy and the impact of blue light hazard, they note that oxidative stress and free radical formation cause damage to cellular structures in the retina, leading to inflammation and lipofuscin deposition. They recommended antioxidants to slow age-related macular degeneration, which is more common after the age of 60.

University of Toledo scientists in the Department of Chemistry published a study in 2018 showing that exposure to Blue Light caused damage and death to photoreceptor cells in the retina.  These photo receptor cells cannot regenerate, speeding up macular degeneration, which leads to blindness. Another 2018 study from Spain, Removal of the blue component of light significantly decreases retinal damage after high intensity exposure, demonstrated a 94% blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light.

Osborne (2017)  has researched the adverse effects of blue light on retinal  mitochondria and found,  “Neurones of the central nervous system have an absolute dependence on mitochondrial generated ATP. Laboratory studies show that short-wave or blue light (400–480 nm) that impinges on the retina affect flavin  and cytochrome constituents associated with mitochondria to decrease the rate of ATP formation, stimulate ROS and results in cell death. This suggests that blue light could potentially have a negative influence on retinal ganglion cell  (RGC) mitochondria”.  Shang (2017), Aadane (2015), Shang (2014), Chamorro (2013) and Behar-Cohen (2011) are among others who have also demonstrated the serious oxidative effects of blue light from digital screens.

Research has shown that non-thermally related radio frequency radiation (RFR) can also cause ocular pathology and eye damage, with the creation of reactive oxygen species (ROS). This is an important consideration with exposure to wireless radio frequency radiation in 2G, 3G, 4G systems. It is an even higher concern for 5G proposed short millimeter wave technology, as this very short high frequency radiation has been shown to create more damage and higher heat concentration with use. Research on the adverse health effects on the eyes for  2G, 3G and 4G let alone 5G are severely lacking while wireless devices are increasingly being placed in close proximity to our brains and eyes. (Fernandez 2018, Sage 2018)

Sleep and Digital Media Use

Researchers are now finding that use of digital devices such as cell phones at night  can interrupt sleep patterns. In a recent study by UCSF, Direct Measurements of Smartphone Screen-Time: Relationships with Demographics and Sleep. scientists concluded,”Longer average screen-times during bedtime and the sleeping period were associated with poor sleep quality, decreased sleep efficiency, and longer sleep onset latency.” A other recent study by Chindamo (2019), Sleep and new media usage in toddlers, found everyday use of a tablet or smartphone raised the odds of a shorter total sleep time and a longer sleep onset latency. Excess screen time is also associated with other health issues as described in this paper by Kenny(2017), United States Adolescents’ Television, Computer, Videogame, Smartphone, and Tablet Use: Associations with Sugary Drinks, Sleep, Physical Activity, and Obesity.

Blue Light Blues: Melatonin Suppression and Breast Cancer

There is growing evidence for adverse ocular effects of blue light emitted from LED screens from computers, cell phones and tablets which can cause direct retinal damage and also inhibit melatonin production in the pineal gland and alter circadian rhythms. Melatonin is a potent antioxidant which is produced in the pineal gland and is also found  in the retina where it modulates genes responsible for circadian rhythms via the ganglion cell layer (Blasiak 2016).   Researchers have found photosensitive retinal ganglion cells (ipRGCs) in the mammalian brain which are not related to image formation but direct circadian rhythms, pupil constriction and alertness through 465nm blue light Vandewalle(2018).

This cascade of biological effects contributes to a host of chronic disease states, including high blood pressure, depression and cancer.

Dr David Blask and colleagues have conducted studies showing that light suppresses melatonin leading to stimulation of breast cancer growth. When they grafted human MCF-7 breast cancer cell xenograft on mice and exposed one to light- light and the other to light-dark environments they found the light- light group had increased cancer cell growth rates. (Blask 2002)   The International Agencyfor Cancer Research (IARC) classified shift work that involves circadian disruption as a “probable carcinogen”. (IARC 2007)

See also  MDSafeTech Scientific Literature  on Sleep Melatonin and Light at Night. 


Harvard Recommendations for Reducing Blue Light Exposure

LED lights from lightbulbs, computers, cell phones, video games and tablets emit blue light from the screen.  Overhead LED lights that are now commonly used also emit more blue light than fluorescent light bulbs, and incandescent light bulbs emit the least blue light. Although much more energy efficient, LED lighting which has largely replaced incandescent in homes, businesses and street lights, may be creating a health risk through complex biologic effects on our melatonin levels and circadian rhythms.  Here are the Harvard guidelines  Blue light has a dark side. Updated August 13, 2018.


Protect yourself from blue light at night (Harvard 2018)

  • Use dim red lights for night lights. Red light has the least power to shift circadian rhythm and suppress melatonin.
  • Avoid looking at bright screens beginning two to three hours before bed.
  • If you work a night shift or use a lot of electronic devices at night, consider wearing blue-light blocking glasses or installing an app that filters the blue/green wavelength at night.
  • Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.


sunglasses-1271913_1920Blue Light Blocking Glasses for Improved Physical and Mental Health

Amber colored blue light absorbing glasses, computer and cell phone screen covers have been developed to block blue light from artificial LED lighting and screens, typically 2-3 hours before bedtime.  More research needs to be done, however, scientists have found that using these blue light blocking devices may promote higher melatonin levels near bedtime thus reducing insomnia.  Evidence is showing the positive effects on blue light blocking glasses not only on sleep quality and timing (Zebrine 2018; Eskai 2016; Burkhart 2009) but also potentially on symptoms of mania in those with manic depressive symptoms by acting as physiologic “dark therapy” not necessarily related to melatonin production (Shirahama 2018; Henriksen 2016). Quality varies with the amount and spectrum of blue light blocked by different glasses. If you are purchasing glasses it is important to get high quality tested glasses and know which frequencies are blocked either full blue light blockage (400-500nm), full blue green blockage (400-550nm ) or specific blue frequencies (i.e.480nm)  blocked on the spectrum (from 400-550nm). In general the more full blue light spectrum blocked the better it will enhance melatonin production. Consumer Reports-3 Blue Blockers Put to the Test 

Apple has introduced “Nightshift” software into their new phones (OS9.3 and above)  that reduces blue light at night. You can access by pressing Settings >Display&Brightness >NightShift and set it to the times you wish the display to reduce blue light. Some research from the Lighting Research Center  has shown that  this Apple setting may not help you sleep as much as anticipated as the brightness of the screen and excess mental stimulation may also be factors on melatonin levels.


Dr. Charles Czeisler Discusses Broad Health Impacts of Poor Sleep

Charles A. Czeisler, MD, PhD, Chief, Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital, explains the critical impacts of sleep on brain function and physical health. He states that sleep is the third pillar of good health along with nutrition and exercise. Lowering blue light at night is component of healthy sleep.   Dr. Czeisler , whose group  has worked with astronauts to reset their circadian rhythms before going into space research, highlights the many bodily systems effected by insomnia including


Doctors Warn That LED City Street Lights Blue Spectrum Can Damage Vision

In  2016 the American Medical Association warned cities that the new energy efficient street light that were being installed to combat global climate change can harm the retina, affect circadian rhythms and sleep patterns. Studies have shown that brighter residential nighttime lighting is associated with sleep disruption. AMA Board Member Maya A. Babu, M.D., M.B.A states, “Despite the energy efficiency benefits, some LED lights are harmful when used as street lighting, The new AMA guidance encourages proper attention to optimal design and engineering features when converting to LED lighting that minimize detrimental health and environmental effects.”

News on Harm From LED Street Lamps


Fatal Collision: Harm from Wireless Eyewear

people-3365369_1920A new 2018 paper,  Fatal Collision: Are Wireless Headsets a Risk in Treating Patients?,   highlights the potential bodily  harm from wearing wireless headsets, augmented reality systems and glass-type eyewear.  Co-authored by Cindy Sage, who is also co- author of the Bioinitiative Report, this review article reveals that these devices, are connected to the internet and have similar radiation (2.4 and 5GHz) to cell phones. An association has been identified between long term cell phone use and brain cancers on the same side of the head. There is also the concern for lack of concentration and distraction when using these devices, similar to cell phones. Damage to eye structures is an obvious concern.

These wireless devices are increasingly being used in medicine (google glass-type wearables)  and by educators but no thought has been given to the harm from long term use. Children are seen in ads wearing wireless headsets for entertainment. It is the next best marketing and sales opportunity in technology.  Sage and Hardell note, “using wireless glass-type devices can expose the user to a specific absorption rates (SAR) of 1.11–1.46 W/kg of radiofrequency radiation. That RF intensity is as high as or higher than RF emissions of some cell phones. Prolonged use of cell phones used ipsilaterally at the head has been associated with statistically significant increased risk of glioma and acoustic neuroma.”  Studies are inadequate to determine safety of these wireless devices long term. There are to date insufficient protective guidelines for adults or children who are increasing using these devices for entertainment, in classrooms and therapeutically in medicine. Precautionary recommendations for use are needed.

Eye Absorption of Radiation from Cell Phones and Virtual Reality

In a new paper Fernandez et al (2018) reveals that young eyes and brains absorb 2 to 5 fold more radiation than that of an adult. He cautions that we need to reexamine regulations and compliance with regards to these devices as testing uses a large adult male (SAM) . Dr. Fernandez also advises precautions proposed by the American Academy of Pediatrics, that young children should not use cell phones. This study indicated virtual reality type devices should also not be used by children. He urges wired connections to reduce children’s  needless exposure to non-ionizing radiation. More research is critically needed in this area as widespread commercial use has already begun.

Absorption of wireless radiation in the child versus adult brain and eye from cell phone conversation or virtual reality (2018) Fernandez et al. 

Fernandez Screen Shot 2018-10-29 at 11.41.15 PM

Reprinted with permission.




Published Studies Physiologic Eye Effects

Newest Articles

Blue Light


Computer Vision Syndrome

  • Prevalence of dry eye in video display terminal users: a cross-sectional Caucasian study in Italy. (2018). Rossi GCM et al. Int. Ophthalmol. https://www.ncbi.nlm.nih.gov/pubmed/29881936
  • Eyesight quality and Computer Vision Syndrome.(2017) Bogdanici CM et al. Rom J Ophthalmic. 2017 Apr-Jun;61(2):112-116. https://www.ncbi.nlm.nih.gov/pubmed/29450383
  • Visual Fatigue Induced by Viewing a Tablet Computer with a High-resolution Display. Kim DJ.  Korean J Ophthalmic. 2017 Oct;31(5):388-393. https://www.ncbi.nlm.nih.gov/pubmed/28914003
  • Computer vision syndrome prevalence, knowledge and associated factors among Saudi Arabia University Students: Is it a serious problem? (2017)  Al Rashid SH. Int J Health Sci (Qassim) 2017 Nov-Dec;11(5):17-19. https://www.ncbi.nlm.nih.gov/pubmed/29114189
  • Exploring the Predisposition of the Asian Eye to Development of Dry Eye. (2016)  Craig JP et al.  Ocul Surf. 2016 Jul;14(3):385-92.  https://www.ncbi.nlm.nih.gov/pubmed/27143647
  • Computer vision syndrome and associated factors among medical and engineering students in chennai. (2014). Logaraj M. Ann Med Health Sci Res. 2014 Mar;4(2):179-85.  https://www.ncbi.nlm.nih.gov/pubmed/24761234
  • [Meibomian gland disfunction in computer vision syndrome]. (2010)  Pimenidi MK. Vests Oftalmol. 2010 Nov-Dec;126(6):49-52.
  • Computer Vision Syndrome: A Review. (2005) Bleh C et al.  Survey of Ophthalmology. May June 2005. Volume 50, Issue 3, Pages 253–262. https://www.surveyophthalmol.com/article/s0039-6257(05)00009-3/abstract https://www.ncbi.nlm.nih.gov/pubmed/29450383
  • Mobile phone related-hazards and subjective hearing and vision symptoms in the Saudi population. (2005) Meo SA and Al-Dress AM.  Int J Occup Med Environ Health. 2005;18(1):537. https://www.ncbi.nlm.nih.gov/pubmed/16052891


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