The Negative Effects of Too Much Screen Time

Functional medicine

Screen time, or time spent engaging with visual screen-based technologies, is a necessity of modern life in the high-tech era. We work in front of computers, communicate via cell phone, and relax in front of the TV. But screen time wasn’t always such an integral part of life. TV only became a popular addition to households between the 1950’s and 1970’s and soon after the first computers became available to the public in 1975. In the 1990’s the cellular revolution occurred. In a matter of 40 years, humans went from virtually no screen time to depending on too much screen time in order to function successfully in the world.  How has this affected us? 

Negative effects of too much screen time

Depression and mental health issues

Researchers in a 2017 study found that adults who have too much screen time (more than 6 hours per day) were more likely to experience moderate to severe levels of depression (Madhav KC, et al; 2017). The possible root of this is the lack of social activity and exposure to the sun. Social activity is known to decrease depression because forming meaningful relationships aids in increasing our self-image, self-esteem and feeling of purpose. 

Screen time is also a sedentary behaviour, and high sedentary levels are linked to depression (Healthline; 2020). 

Sleep deprivation

Digital screens emit a type of light called blue light. An excessive amount of blue light can cause your body to lower production of the sleep hormone, melatonin. This hormone helps control your circadian rhythm (your body’s internal clock), thus too much screen time can interfere with your ability to shut down at night. Screen time just before bed is the most harmful as you are receiving a dose of blue light, instead of winding down with the naturally dimming light of nightfall (Knight, C; date unknown). 

Visual impairment 

Whilst there is little evidence to suggest that too much screen time does significant damage to eyes in the short-term, too much screen time strains your eyes and leaves them feeling dry. In the long-term this can also lead to impaired retinal cells.  Impaired retinal cells have been linked to problems like age-related macular degeneration (AMD), which can cause blurred vision. There is no cure for AMD, but the condition can be managed (N Vision; 2020).


Too much screen time can cause headaches and migraine. A 2015 study found that individuals who got 2 hours or more of screen time were more likely to get a headache or migraine (Montagni, I, et al; 2015). 

Symptoms of a screen headache include (Lindberg, S; 2021):

  • headache behind the eyes
  • eye strain
  • blurry vision
  • tight neck and shoulder muscles
  • dry eyes
  • sensitivity to light


Being constantly hunched over (like so many people tend to do with their smartphones) as a result of too much screen time affects your posture and can cause stiffness and pain to the neck, shoulders and back. Smart phones are not the only culprit though. Lazing incorrectly in a couch or hunching over your computer screen can cause similar issues. To read more about the correct sitting position read this article on good posture.

The positive effects of screen time

  • Educational value 

Screen time can have educational value. Children are able to use digital devices for school-related homework and research (Mediclinic Info hub; 2020). 

  • Improved co-ordination 

Video game screen time can be positive when controlled and age-appropriate by improving motor skills and co-ordination (Mediclinic Info hub; 2020). 

  • Connecting with the world

Internet tools, texting, and shared video games are easy and fun ways to socialize and communicate. Learning how to use digital platforms can also prepare children for the working world (Mediclinic Info hub; 2020).

Combatting too much screen time 

We’ve had a look at the positive and negatives of screen time, and the evidence that too much screen time can be detrimental to your health is overwhelming. But how do you combat screen fatigue? 

Green time 

Exposure to, or time spent in nature, is referred to as ‘green time’. Green time can do wonders to combat the effects of too much screen time. Being in nature will help to keep your circadian rhythm in check, assisting with sleep deprivation. It will also lift your mood thanks to sunlight and physical activity, which also combats the negative effects screen time has on your posture. Finally, being out in nature will give your eyes a well-deserved break. Remember moderation is key and you should avoid becoming sunburnt or over-exerting yourself physically (Oswald T, et al;2020). 

The 20-20-20 rule 

The 20-20-20 rule is recommended by optometrists to help combat the fatigue caused to your eyes from too much screen time. The rule suggests that for every 20 minutes spent using a screen, you should try to look away at something that is 20 feet away from you for a total of 20 seconds (it takes 20 seconds for your eyes to completely relax). There are many apps to help remind you to look up every 20 minutes – so there’s no excuse (Legg T; 2017).

A healthy balance

Too much screen time can be devastating to your health but a limited amount of managed and mindful screen time can be beneficial, and is of course necessary in today’s high-tech era. Keeping a healthy balance is key.  

Based on recommendations by the American Academy of Paediatrics, children aged between two and five should spend no more than one hour per day in front of a screen, while older children, teenagers and adults should be mindful of balancing media use with other healthy behaviours.

When engaging with screen be mindful of the positive benefits you stand to gain and try to orientate your screen time around those benefits. 

More advice about screen time 

Dr Matt Le Roux works with a variety of concerns, ranging from acute, chronic pain and complex injuries to nutritional, lifestyle, and performance enhancements. He is specialised in Sports Chiropractic. To get in touch, visit our contact page.


  1. Madhav KC, et al; 2017. Association between screen time and depression among US adults.
  2. Healthline; 2020. The Mental Health Effects of Being Constantly Online.
  3. Knight, C; date unknown. Screen Time and Insomnia.
  4. N Vision; 2020. Screen time & your eyes: What the research says.
  5. Montagni, I, et al; 2015. Screen time exposure and reporting of headaches in young adults: A cross-sectional study.
  6. Lindberg, S; 2021. Screen Headaches and Migraine: Can You Prevent Them?
  7. Mediclinic Info hub; 2020. The positives and negatives of screen time.
  8. Oswald T, et al;2020. Psychological impacts of “screen time” and “green time” for children and adolescents: A systematic scoping review.
  9. Legg T; 2017. How Does the 20-20-20 Rule Prevent Eye Strain?

Dr. Matt le Roux is a man of many talents: chiropractor, sports scientist and functional medicine practitioner. His science-based approach motivates him to explore the synergy between health and performance that changes the way you move, live, train, think, and eat.

Dr Matt le Roux

Chiropractor, Functional medicine practitioner

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