How is screen time affecting your vision?

Learn what CVS is and what you can do to help decrease the symptoms.


How many hours a day do you spend looking at a screened piece of technology?

If you are like most of us, your answer could be anywhere between two and ten hours a day. You may or may not be surprised by this number if you work on a computer, own a smartphone or perhaps have a mild addiction to your Xbox, Netflix or Kindle. But have you ever felt a pounding, throbbing or aching feeling in your head after using your device? You may have Computer Vision Syndrome, or more commonly CVS. Computer Vision Syndrome is a term optometrists have given this form of eyestrain for people who look at device screens frequently.

People who look at screened devices all day require their eyes to focus on screen text, which is not as sharp as text found on a piece of paper. We also use our eyes ciliary muscles for extended periods of time to help us focus at short distances. Both of these can lead to eye discomfort and vision strain.


One way the Ontario Association of Optometrists (OAO) suggests we combat the symptoms (which fade away after use of the device), is to follow the 20-20-20 rule. The 20-20-20 rule means we should stop staring at our devices every 20 minutes and focus on something else 20 feet away for at least 20 seconds to help give our eye muscles a break and rehydrate our eyes.

Check out the video below from the Ontario Association of Optometrists, created to help digital device users break bad screen habits affecting eye health:

Here are four ways you can help reduce digital eyestrain with links to resources for further reading:

  1. Adjust your Display Settings
  2. User Proper Lighting
  3. Exercise your Eyes
  4. Increase Text Size & Colour

Share your tips below for helping combat eye fatigue from digital device usage; we’d love to learn more tricks!

Are there Health Risks with WiFi?

Radiation is used to treat malignant tumors, x-rays can help doctors diagnose internal injuries, and we are all exposed to various types of radiation through radio waves, televisions, and cellphones. Lately, questions have been raised in Ontario to the health risks related to WiFi emissions.

In recent years, leaders in the health field, politicians, and even school boards have attempted to mitigate the perceived threat of exposure to radio-frequency (RF) electromagnetic (EM) radiation, on which WiFi, radios, microwaves, Bluetooth, and mobile and cordless phones operate. The perceived threat of RF exposure might have been exacerbated when, in May 2011, the World Health Organization (WHO) released a document from the International Agency for Research on Cancer (IARC) which classified these types of EM emissions as a Group 2B, “possibly carcinogenic” agent to humans – alongside with other substances like aloe vera and carrageenan – for which the evidence of deleteriousness is uncertain. Since the update of this WHO document, many health experts have raised concerns about the risks associated with mobile phones; political leaders have gone on the record warning the public of potential health risks that can be incurred through the use of WiFi, and unions, including the Canadian Teachers’ Federation, are calling for a moratorium on WiFi device use in schools suggesting an outright ban of the technologies.

However, do we actually know the health effects of RF exposure, and, in particular, the risks associated with WiFi use? Let’s look at some of the potential health hazards related to WiFi use; what WiFi supporters are saying, and methods of lowering personal exposure to WiFi emissions.

Potential Health Concerns

1. Disturbances to Sleeping Patterns

A study conducted in 2007 by Hung, Anderson, Horne, and McEvoy evaluated low-frequency modulation transmissions from cellphones and its impact on sleep. Study participants were exposed to emissions produced by real phones through ‘talk’, ‘listen’, and ‘standby’ modes or interacted with sham (fake) phones. Subjects who engaged in talk mode had a markedly delayed sleep onset in relation to participants who engaged in listen and sham modes. Researchers also noticed that different frequencies and strengths in emission modulations (2, 8, and 217 Hz) could affect sleep onset differently.

Many researchers have concluded that keeping a phone near your bed, being exposed to in-home WiFi signals, or interacting with WiFi technologies prior to engaging in sleep can create chronic sleep disorders as EM pollution interferes with falling asleep and establishing healthy sleeping patterns (Bordely, Huber, Graf, Fuchs, Gallmann, & Achermann, 1999; Hung, Anderson, Horne, & McEvoy, 2007; National Sleep Foundation, 2014). Sleep deprivation is just the beginning to larger health problems. Decreases in sleep duration and delayed sleep onset can result in the development of depression and anxiety (Adams, Daly, & Williford, 2013; Cain & Gradisar, 2010; Harbard, Allen, Trinder, & Bei, 2016; Munezawa et al., 2011).

2. Effects to Cell Function and Growth

Exposure to non-ionizing, low-frequency EM emissions from WiFi technology and cellular devices can disrupt the development and growth of cells (Makker, Varghese, Desai, & Agarwal, 2009; Hardell & Sage, 2008). A 2009 Austrian study found that the expression levels of 38 cytoskeletal proteins (proteins that form the supporting tissue of a cell) had changed after being exposed to cellphone EM radiation (The AUVA Report, 2009). These researchers were able to determine that different tissues had varying sensitivities to EM emissions, and that cellphone radiation exposure caused “a notable change in protein synthesis profiles” (AUVA Report, 2009, p. 4). Consequently, members of the population with disease or pathophysiological conditions might see their symptoms worsen and some neurological disorders can be triggered by high rates of protein synthesis (AUVA, 2009; Makker et al., 2009).

3. Impedes Neural Function in Females

A study conducted at the National Technical University of Athens examined the influence of electromagnetic fields, similar to those that are emitted by WiFi systems, on activity within the brain (Maganioti et al., 2014). Fifteen male and fifteen female subjects performed short term memory tasks without being exposed to any EM emissions. These participants were then exposed to a 2.4 GHz WiFi access point at a distance of 1.5 meters from the right side of the head. Each non-exposure and exposure interval lasted 45 minutes. Two weeks later, participants then performed the same memory tasks in the same intervals two weeks later. Researchers noticed that in the presence of radiation, the alpha and beta band energies of male subjects were unaffected. However, in female subjects, these same energies were significantly lower. Researchers evaluated the condition of delta and theta band energies in both male and female participants, with no noteworthy effect between genders. Conversely, there was a significant interaction effect on the alpha and beta wave forms in some of the participants (Maganioti et al., 2014). This study has shown that WiFi signal emissions can influence normal physiological conditions by changing gender related corticol excitability in the alpha and beta rhythmic waveforms.

What do we know?

Different technologies emit different levels of EM radiation. Vecchia et al., (2009) from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) conducted reviews on the health effects of EM emission exposure, particularly the radiation that is emitted by cellphones and WiFi access points. The commission concluded that mobile phones radiation exposure is localized to the head, and is relatively low EM intensity radiation. WiFi emissions are absorbed by the whole body at much lower intensities than those produced by mobile phones. When study participants reported symptoms, such as headaches, nausea, or fatigue, researchers were not able to causally relate EM emission exposure to these changes in health conditions. These conclusions supported findings from Public Health England where signals from WiFi routers are “typically 0.1 watt (100 milliwatts) …and the results so far show exposures are well within the internationally-accepted guidelines from the International Commission on Non-Ionizing Radiation Protection (ICNIRP).” Whether these small changes in functional performance are significant remains elusive, and more robust research is required to determine the nature and consequences of these effects as they relate to EM emission exposure.

The ICNIRP report (2009) also noted that there are some indications that EM emissions could influence blood flow in different cerebral regions, thought to correlate to changes in neural activity, particularly in the alpha and beta rhythms, during and following EM radiation exposure. However, it is unclear as to the reliability of findings because no consistent effects on cognitive performance have been found.

Regarding the impacts of RF radiation on cell development and growth, a review of evidence by Health Canada stated, “As long as RF energy levels remain below Health Canada’s RF safety guidelines, current scientific evidence supports the assertion that RF energy emissions from Wi-Fi devices are not harmful.” These conclusions are in line with the findings with other international bodies and regulators, including the WHO, the ICNIRP, Public Health England, and the Institute of Electrical and Electronics Engineers (IEEE).

Potential Precautions

Ultimately, it is the choice of the user to take necessary precautions to guard against potential harmful emissions. WiFi technology has only been a ubiquitous technology for a short period of time (between 15-20 years). Even Health Canada, the WHO, and the IEEE have recommended that more research is needed to determine if there are links between RF radiation, cancer, and cognitive dysfunction.  But in the meantime, if you wanted to lower RF emission exposures from mobile phones for yourself and your children, you can follow these guidelines from the American Academy of Pediatrics Cell Phone Safety Tips for Families:

  • Use text messaging when possible, and use cell phones in speaker mode or with the use of hands-free kits.
  • When talking on the cell phone, try holding it an inch or more away from your head.
  • Make only short or essential calls on cell phones.
  • Avoid carrying your phone against the body like in a pocket, sock, or bra. Cell phone manufacturers can’t guarantee that the amount of radiation you’re absorbing will be at a safe level.
  • If you plan to watch a movie on your device, download it first, then switch to airplane mode while you watch in order to avoid unnecessary radiation exposure.
  • Keep an eye on your signal strength (i.e. how many bars you have). The weaker your cell signal, the harder your phone has to work and the more radiation it gives off. It’s better to wait until you have a stronger signal before using your device.
  • Avoid making calls in cars, elevators, trains, and buses. The cell phone works harder to get a signal through metal, so the power level increases.

Additionally, WiFi users can lower RF radiation exposure in several ways:

  • Turn off your WiFi before sleeping.
  • Eliminate WiFi by installing ethernet cable or ActionTec box sets.
  • Disable wireless functions on your devices when not in use.

Have you experienced any health effects from RF exposure? Do you take precautions to minimize your RF exposure? Please provide any additional information, research, and experiences in the comment section below.


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