What is computer vision syndrome?
Computer vision syndrome (CVS) is a term used to describe a collection of visual symptoms (some definitions include non-visual symptoms like shoulder and neck pain) resulting from spending extended time viewing a computer screen. These symptoms include:
- Eye strain
- Dry Eye
- Blurred vision
- Double vision
As computer time has increased in the workplace, these symptoms have become more common. But it is not just the working population spending more time on computer screens, it is children too, as the computer becomes a common tool in the classroom. A 2018 study of college students found up to 50% had some of these symptoms (1). A second study found up to 77% of surveyed students had symptoms consistent with CVS (2).
The causes of computer vision syndrome
The causes of computer vision syndrome can be related to the environment and to the users own visual skills. (3)
In the environment, glare, poor lighting, and poor viewing distance are a contributing factor to a user developing CVS.
Computer monitors offer a lessor quality image when compared to reading from paper. A computer renders text and images using small dots of light (called pixels). Lower resolution (less pixels) monitors do not present as sharp of an image and are related to more eye strain and headaches (4). The color contrast in the monitors as well as the glare and reflection from screen surfaces can also increase symptoms. Slower refresh rate in some monitors can also cause discomfort.
Visual problems such as undiagnosed refractive error, ocular motor problems, and poor tear quality can also contribute to symptoms. Computer users tend to blink less causing dry eye conditions which may feel like “grittiness” in the eyes.
Preventing Computer Vision Syndrome
Preventing CVS starts with a visit to an eye care professional. The user should be in lenses that provide the best possible acuity. Many doctors can prescribe glasses made to have the best possible vision at a specific distance to help reduce eye strain. A binocular assessment will also find any eye movement problems affecting extended computer use. The eye doctor can also assess tear quality and make recommendations for improving or supplementing with artificial tears. They may also recommend in-clinic treatment of binocular vision problems to improve near vision focusing.
Extended computer viewing can be very exhausting to the eyes, so a rest break is recommended every 20 minutes for 20 seconds, by looking 20 feet away. This is called the 20/20/20 rule. These breaks can help reduce the likelihood of developing CVS as they give the eyes a chance to rest from the strain of the computer screen.
As mentioned, a quality monitor with a glare-free screen should be used to reduce eye strain. Environmental lighting also plays a significant role as well, with bright lights, window glare, and fluorescent lights all contributing to discomfort. Adjusting the ambient lighting and reducing glare with window blinds or filters to a comfortable level can be helpful in reducing CVS.
Limiting Screen time
Limiting screen time seems like a good idea but is it actually feasible? With many schools now making extensive use of computers in the classroom, the recommended limit of two hours a day is far exceeded before a child returns home from school. With these factors, computer vision syndrome will be a problem not going away anytime soon.
(1)Mowatt, L., Gordon, C., Santosh, A. B., & Jones, T. (2018, January). Computer vision syndrome and ergonomic practices among undergraduate university students. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28980750
(2)Al Rashidi, S. H., & Alhumaidan, H. (2017). Computer vision syndrome prevalence, knowledge and associated factors among Saudi Arabia University Students: Is it a serious problem? Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/29114189
(3)Gowrisankaran, S., & Sheedy, J. E. (2015). Computer vision syndrome: A review. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/26519133
(4)Loh, K., & Redd, S. (2008, December 31). Understanding and preventing computer vision syndrome. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4170366/