Scientific Literature

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

It is well established that eye structures are harmed by exposure to UV radiation. Points De Vue 2017 That is why ophthalmologists and optometrists always advise wearing protective sunglasses when outdoors. Newer research is now showing that there are a host of other serious risks associated with exposure to digital screens.

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.  Published data is also adding  LED blue light as a true risk for retinal damage and circadian rhythm disruption: Screen time as a risk for dry eye syndrome and computer vision syndrome along with circadian rhythm disruption from blue light and night at light with LED wavelengths. Sleep disruption is associated with a host of chronic diseases, including cancer, as well as poor learning performance.


Cataracts on the Rise

There is a continued rise in 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 screen at home and now mandated at school, there are even more serious concerns.

Retinal Oxidative Eye Damage and Blindness from Blue Light

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. This speeds macular degeneration, which leads to blindness.

Osborne et al (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” .

Research has shown that non-thermally related radio frequency radiation (RFR) can 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)


Blue Light Blues: Melatonin Suppression, Retinal Damage and Cancer

There is growing evidence for adverse ocular effects of blue light emitted from computers which can cause direct retinal damage and also inhibit melatonin production in the pineal gland and alter circadian rhythms. This cascade of biological effects contributes to a host of chronic disease states, especially cancer.  Dr David Blask and colleagues have conducted studies showing that light suppresses melatonin leading to stimulation of 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. 


Reducing Blue Light Exposure: Harvard Recommendations

LED lights from computers, cell phones 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.


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.


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 but does not give recommendations on screen time.


Doctors Warn That LED City Street Lights Can Damage Vision

In  2016 the AMA 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. 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


Published Studies Physiologic Eye Effects

New 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.
  • Eyesight quality and Computer Vision Syndrome.(2017) Bogdanici CM et al. Rom J Ophthalmic. 2017 Apr-Jun;61(2):112-116.
  • Visual Fatigue Induced by Viewing a Tablet Computer with a High-resolution Display. Kim DJ.  Korean J Ophthalmic. 2017 Oct;31(5):388-393.
  • 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.
  • 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.
  • 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.
  • [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.


Non-ionizing Radiofrequency Radiation Exposure

Related Articles on Eye Damage and EMF exposures

  • Ultraviolet damage to the eye revisited: eye-sun protection factor (E-SPF®), a new ultraviolet protection label for eyewear. (2013). Behar-Cohen F et al.  Cain. Ophthalmology 2014; 8: 87–104.
  • Ultraviolet phototoxicity to the retina. (2011). Glickman RD. Eye Contact Lens. 2011 Jul;37(4):196-205.