Mainly, these are the most prominent:
Eye Strain: Dryness, Irritation, Blurred vision, Headaches
Musculoskeletal Problems: Neck pain,Back pain,Shoulder pain,Repetitive strain injuries
Sedentary Lifestyle: Obesity and Cardiovascular diseases
Mental Health Issues: Stress, Anxiety, Depression
Sleep Disruptions: Insomnia, Poor sleep quality
I will say that mental health problems are the most dangerous. Children today do not go outside to play. Todlers do not even eat without an iPad or laptop. We socialize through computers.
Eye Strain (Computer Vision Syndrome) 1:
Reference: Sheppard, A. L., & Wolffsohn, J. S. (2018). Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmology, 3(1), e000146.
Link: https://bmjophth.bmj.com/content/3/1/e000146
Musculoskeletal Problems:
Reference: Waersted, M., Hanvold, T. N., & Veiersted, K. B. (2010). Computer work and musculoskeletal disorders of the neck and upper extremity: A systematic review. BMC Musculoskeletal Disorders, 11, 79.
Link: https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/1471-2474-11-79
Reference: Gerr, F., Marcus, M., Ensor, C., Kleinbaum, D., Cohen, S., Edwards, A., Gentry, E., Ortiz, D. J., & Monteilh, C. (2002). A prospective study of computer users: II. Postural risk factors for musculoskeletal symptoms and disorders. American Journal of Industrial Medicine, 41(4), 236-249.
Link: https://onlinelibrary.wiley.com/doi/abs/10.1002/ajim.10066
Reference: Griffiths, K. L., Mackey, M. G., Adamson, B. J. S. (2007). The impact of a computerized work environment on professional occupational groups and behavioral and physiological risk factors for musculoskeletal symptoms: A literature review. Journal of Occupational Rehabilitation, 17, 743-765.
Link: https://link.springer.com/article/10.1007/s10926-007-9096-5
Sedentary Lifestyle:
Reference: Owen, N., Sparling, P. B., Healy, G. N., Dunstan, D. W., & Matthews, C. E. (2010). Sedentary behavior: emerging evidence for a new health risk. Mayo Clinic Proceedings, 85(12), 1138-1141.
Link: https://www.mayoclinicproceedings.org/article/S0025-6196(11)60723-7/fulltext
Mental Health Issues:
Reference: Taris, T. W., Kalimo, R., & De Boer, E. (2002). Ethnic differences in computer use-related psychosocial stress among white-collar employees in Finland. European Journal of Work and Organizational Psychology, 11(2), 183-196.
Link: https://www.tandfonline.com/doi/abs/10.1080/13594320244000166
Sleep Disruptions:
Reference: Chang, A. M., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232-1237.
Link: https://www.pnas.org/content/112/4/1232