“A recent investigation of over 2000 American children between 8 and 18 years of age reported that in an average day they spend approximately 7.5 h using entertainment media, 4.5 h watching TV, 1.5 h on a computer and over an hour playing video games.” 
If we factor in 8 hours of sleep, almost 16 hours of each day are spent in sedentary inactivity… which by any standard is far too much for anyone. It has been known for a few decades or more that prolonged computer use is detrimental to the eyesight of adults, causing a myriad of vision issues including myopia, presbyopia, and astigmatism. With the increase in computer usage by children, the question is to what degree is their vision negatively impacted? Research is showing that Computer Vision Syndrome (CVS) has even more severe impact on children than it does on adults.
WebMD explains the syndrome thus:
“Computer vision syndrome is similar to carpal tunnel syndrome and other repetitive stress injuries at work. It occurs when you’re carrying out the same motion over and over again. Just like those other repetitive stress injuries, computer vision syndrome can get worse the longer you continue the activity.” 
The eyes have a natural focusing feature which develops as a child ages based on frequent alternation between near and far stimuli. Traditional activities, such as sports or social interaction in large open spaces such as children’s museums or parks, are necessary to this developmental process. When such activities are replaced with extended periods of time on a computer, tablet device, or smart phone, however, this process is retarded or even halted. One study revealed:
“Prolonged activity without a significant break can cause accommodative problems and eye irritation. Accommodative problems may occur as a result of the eyes’ focusing system ‘locking in’ to a particular target distance. In some cases, this may cause accommodation spasm.” 
Because children lack “vision experience,” another study notes:
“… children often accept blurred vision caused by a refractive error, because they think everyone sees the way they do. Uncorrected hyperopia can cause eye strain, even when clear vision can be maintained.” 
It is worth noting that between 2000 and 2007, approximately 37 million American children were diagnosed with CVS. 
Recommendations: Research shows that the following recommendations should deter the onset of CVS in children:
- Limit computer sessions to no more than 5 minutes per year of age in each setting, e.g. a 4-year-old should not be on a computer longer than 20 minutes at one sitting. Children under 2 should not be exposed to a computer or electronic device (including television) at all. 
- Allow at least two hours between sessions.
- Limit computer usage to no more than 1 session per day for children under 5, 2 sessions per day in elementary school, and 3 sessions per day for children of middle school age. Children of high school age (15-18) should take a 10-minute break every hour they are on the computer, about mid-way through the hour. 
- Have children’s eyes checked often. 
- Always maintain a viewing distance of at least 40 cm (153⁄4 in) from any electronic device. 
Notes & References
- Generation M2: Media in the Lives of 8- to 18-Year-Olds. A Kaiser Family Foundation Study. The Henry J. Kaiser Family Foundation: Menlo Park, CA, 2010. , & .
- American Optometric Association: “Computer vision syndrome (CVS).” In Nazario, B. (2012). Computer vision syndrome. WebMD. Online: http://www.webmd.com/eye-health/computer-vision-syndrome?page=1.
- Blehm, C., Vishnu, S., Khattak, A., Mitra, S., & Yee, R. W. (2005). Computer vision syndrome: a review. Survey of ophthalmology, 50(3), 253-262.
- Barar A, Apatachioaie ID, Apatachioaie C, Marceanu-Brasov L. Ophthalmologist and computer vision syndrome. Oftalmologia. 2007; 51:104–109.
- Kozeis, N. (2009). Impact of computer use on children’s vision. Hippokratia, 13(4), 230–231.
- Yan, Z., Hu, L., Chen, H., & Lu, F. (2008). Computer Vision Syndrome: A widely spreading but largely unknown epidemic among computer users. Computers in Human Behavior, 24(5), 2026-2042.
- American Academy of Pediatrics. Media and children. Online: https://www.aap.org/en-us/advocacy-and-policy/aap-health-initiatives/Pages/Media-and-Children.aspx
- Izquierdo JC, Garcνa M, Buxó C, Izquierdo NJ. Factors leading to the Computer Vision Syndrome: an issue at the contemporary workplace. Bol Asoc Med P R. 2004; 96:103–110.
- American Optometric Association: Computer vision syndrome threatens returning students. In Nazario, B. (2012). Computer vision syndrome. WebMD. Online: http://www.webmd.com/eye-health/computer-vision-syndrome?page=3.
Rosenfield, M. (2011). Computer vision syndrome: a review of ocular causes and potential treatments. Ophthalmic and Physiological Optics, 31(5), 502-515.