As technology has evolved, digital screens have become an integral part of our daily lives. We use them for work, entertainment, communication, and information gathering. However, prolonged use of digital devices can lead to Digital Eye Strain (DES), also known as Computer Vision Syndrome (CVS). DES is an extension of previously described visual and ocular symptoms (asthenopia) with demanding near tasks prior to the “digital age”.
Most people have a clear and comfortable vision while reading, doing computer work, or using a smartphone. However, about 10 to 20% experience visual and ocular symptoms when engaged in near work with a challenging cognitive load. Additionally, over 50% experience Digital Eye Strain mainly due to the increased amount of time spent using a digital screen.
Signs and Symptoms of Internal and External Digital Eye Strain
Digital screens can cause both external (ocular) and internal (visual) DES symptoms. External symptoms include eye dryness, burning, irritation, and protective tearing. These symptoms can be worsened by factors such as dry eye disease, reduced blink rate, smaller font size, reduced letter contrast, glare from surrounding light environment or digital screen, and duration of screen use. Additionally, incomplete blinking (upper lid does not cover the entire front surface of the eye) increases from 5 to 15% of blinks with digital screen use.
Internal symptoms of DES include eye strain, tired eyes, blurred vision, frontal headaches, and loss of concentration with binocular use of the two eyes. These symptoms can be exacerbated by factors such as gaze angle from the normal reading position, the smaller size of text, the closeness of the digital screen, insufficient optical correction, eye teaming dysfunction (also called vergence dysfunctions), eye focusing dysfunction (also called accommodative dysfunctions), and eye tracking/movement dysfunction (also called oculomotor dysfunctions of saccades, pursuits, and fixations).
It's worth noting that visual symptoms are similar with both digital and printed material use, but are magnified due to the increased time spent on digital screens. Additionally, digital screens produce more light, including blue light, than printed paper, which can also contribute to DES symptoms. Self-report questionnaires, such as the Rasch-based Computer-Vision Symptom Scale (CVSS17), Computer Vision Syndrome Questionnaire (CVS-Q), and existing vision-quality of life tools like the Vision Quality Scale (VQS) and COVD-QOL, are available to quantify the level of DES.
Does Blue Light Contribute to DES?
There is a lot of concern about the effects of blue light on our health, but the evidence is not clear. While blue light can reduce melatonin production, which is important for sleep, there is little research to support the idea that it causes visual symptoms.
Additionally, there is no harm or photochemical effect on the retina from blue light, except in very rare cases after long periods of continuous exposure. It's also important to keep in mind that the amount of blue light from digital screens is much lower than what we are exposed to outside on a sunny day.
Finally, while the risk of long-term exposure to blue light from digital screens is not yet fully understood, outdoor workers have been safe from blue light over the decades and needed protection from UV light instead.
Myopia and Screen Time
While digital screen use may increase the risk of myopia (nearsightedness) development, there is no conclusive evidence that it is a direct cause. Myopia is a complex condition influenced by many factors, including genetics and lifestyle.
Studies have shown that outdoor time, specifically exposure to natural light, may help prevent myopia development in children. Therefore, it is important to balance digital screen time with outdoor activities, especially for children. Additionally, following the 20-20-20 rule (taking a 20-second break every 20 minutes to look at something 20 feet away) may also help reduce the risk of myopia development and other visual symptoms associated with digital screen use.
Overall, while digital communication has many benefits, it is important to be mindful of its potential impact on visual health and take steps to mitigate any negative effects. This can include taking breaks, adjusting screen settings, and seeking professional advice if necessary.
How Can Screen Time and Social Media Impact Mental Health?
The impact of technology use and social media on mental well-being is an important and complex issue. While technology and social media can have many benefits, including greater socialization, entertainment, and opportunities for learning, excessive use can lead to negative consequences. Some studies have linked high daily smartphone or social media use with increases in depression, anxiety, ADHD, OCD symptoms, and hostility/aggression. Additionally, excessive screen time can interfere with everyday social and family interactions, affect physical and mental health, and impinge on sleep patterns.
For children and adolescents, excessive screen time has been associated with inattention problems, increased risk of meeting diagnostic criteria for ADHD, and decreased integrity of brain white matter tracts, associated with language and literacy skills, in preschool children. Increased access to mobile and online environments can also increase exposure to online risks of cyber harassment, peer aggression and abuse, stalking, cyber-bullying, and sexting beyond traditional physical bullying which could negatively impact mental health.
It is important to note that the overall intense use of digital technologies giving rise to negative mental outcomes may be a result of other variables affecting mental well-being. Nonetheless, it is clear that there are risks associated with the excessive use of technology and social media, and individuals, parents, and educators should be aware of these risks and take measures to reduce them.
Screen Time Recommendations
To minimize the effects of digital eye strain, we recommend the following:
- Sit about 2 feet away from the computer screen
- Make sure the center of the computer monitor is slightly lower than eye level
- Use a larger font size
- Follow the 20/20/20 rule (look at least 20 feet away for at least 20 seconds after 20 minutes of near work)
- Increase time spent outside
- Consider computer glasses with blue light-blocking coating
- Reduce or eliminate digital screen use 2-3 hours before sleep
- Pay attention to sleep quality and duration
Ocular Recommendations for Children:
- 0-2 years old: No screen time except for live video chatting with parental supervision and support
- 2-5 years old: No more than 1 hour per day of age-appropriate, educational content with parental supervision
- 5-18 years old: Ideally no more than 2 hours per day of recreational screen time with regular breaks; individual screen time plans should be considered based on development and needs
- Ensure screen time is not a routine part of child care for children younger than 5 years old
- Regular "screen-free" times are recommended, especially during family meals, gatherings, and play dates with other children
- Monitor screen time content and prioritize educational, age-appropriate, and interactive programming
- Annual eye examinations are recommended for children to ensure ocular health and visual skills are maintained
In conclusion, digital eye strain is a prevalent issue that can negatively affect your vision and overall health. It’s important to recognize the symptoms and take measures to prevent them to ensure the healthy and comfortable use of digital devices. For a more in-depth analysis of the relationship between screen time and mental health, click here to learn more.