What is VDT syndrome?
A VDT (visual display terminal) is any device that shows information on a screen: monitors, laptops, tablets and smartphones. VDT syndrome is an umbrella term for the eye problems, musculoskeletal symptoms and headaches associated with long use of these devices. The eye symptoms alone are also called computer vision syndrome (CVS) or digital eye strain.
It drew attention as an occupational health issue in the 1980s as office automation spread, and in Korea neck, shoulder and arm disorders from VDT work became part of the debate on occupational disease. Today it affects almost everyone, including students and remote workers.
Main symptoms
- Eyes: fatigue and pain, dryness, burning, redness, blurred vision, slow refocusing and glare sensitivity.
- Musculoskeletal: stiff neck and shoulders, back pain, forward head posture ("text neck"), wrist and finger pain and conditions such as carpal tunnel syndrome.
- Other: headache, fatigue and reduced concentration.
Causes
- Reduced blinking: concentrating on a screen sharply lowers blink rate, so the tear film evaporates and the eyes dry out. Tsubota and Nakamori (1993) linked reduced blinking and greater ocular surface exposure during VDT work to dry eye.
- Accommodative strain: focusing on a near screen for long periods keeps the focusing muscles contracted. Uncorrected refractive errors or presbyopia make it worse.
- Screen and lighting: reflections and glare, mismatched brightness, small text and poor screen placement all add to symptoms.
- Posture and repetition: a monitor that is too low or too close bends the neck, and poorly placed keyboards and mice load the wrists and shoulders, especially without breaks.
Prevention and management
- Regular breaks: the widely recommended "20-20-20 rule" is to look at something 20 feet (about 6 m) away for 20 seconds every 20 minutes. Standing and stretching for a few minutes each hour also helps.
- Screen placement: place the monitor about an arm's length (50–70 cm) away with the top at or slightly below eye level so the gaze is directed slightly downward.
- Posture: back supported, feet on the floor, elbows near 90 degrees and wrists straight.
- Lighting and settings: avoid reflections from windows and lamps, match screen brightness to the room and enlarge text.
- Eye care: blink deliberately, use artificial tears if needed and check that glasses or lenses are correct. Persistent symptoms call for an ophthalmologist or rehabilitation specialist.
Occupational health and policy
VDT work is managed as a musculoskeletal-risk task, and employers are responsible for improving workstations and ensuring breaks. As more screen work is done by platform workers and dependent contractors with weaker labor-law protection, protecting their health has become an issue.
Limits of the research
- Studies use different diagnostic criteria and questionnaires, so reported prevalence varies widely; Sheppard and Wolffsohn (2018) called for standardized measurement.
- Evidence that blue-light-filtering glasses reduce eye strain is generally judged insufficient.
- Most symptoms are temporary, but long-term effects on vision need more research.
References
- Tsubota, K., & Nakamori, K. (1993). Dry eyes and video display terminals. New England Journal of Medicine, 328(8), 584.
- Blehm, C., Vishnu, S., Khattak, A., Mitra, S., & Yee, R. W. (2005). Computer vision syndrome: A review. Survey of Ophthalmology, 50(3), 253–262.
- Rosenfield, M. (2011). Computer vision syndrome: A review of ocular causes and potential treatments. Ophthalmic and Physiological Optics, 31(5), 502–515.
- Sheppard, A. L., & Wolffsohn, J. S. (2018). Digital eye strain: Prevalence, measurement and amelioration. BMJ Open Ophthalmology, 3(1), e000146.