The 50-Centimetre Rule: What Ergonomics Research Actually Says About Saving Your Eyes and Back at a Desk

Screens belong 50 to 70 centimetres from the face. The top edge of the monitor should sit at or slightly below eye level, tilted back by roughly 20 degrees. Those two numbers alone prevent a large share of the redness, burning, grit-in-the-eye sensation and watering that send desk workers hunting for eye drops — and they matter more than ever now that so many of us work from home.

An online study by the Institute for Prevention and Occupational Medicine, together with the Institute for Occupational Safety of the DGUV (Germany's statutory accident insurance body), warns that poor conditions at a home screen workstation raise the risk of exactly those complaints.

The shift in where work happens explains the urgency. According to the social health@work study, 56.1 percent of respondents work at least partly on the move, and 92.1 percent of them use the home office among other locations. Before the pandemic, mobile work averaged 15.9 hours a week; during the coronavirus period that figure climbed to 35.7 hours.

Measuring up: desks, chairs and the space between them

Budget roughly 1.5 to 2 square metres per person for a workstation. A laptop-only setup needs a desk 100 to 120 centimetres wide; add a second monitor or a lot of paperwork and 140 to 160 centimetres is the advised width. The desktop should be at least 60 centimetres deep, with 70 to 80 centimetres considered comfortable. Experts recommend leaving a gap of 19 to 28 centimetres between chair and table.

To find the right seat height, measure while wearing work shoes on a firm surface: feet flat, tape measure vertical from the floor to the underside of the thigh at the back of the knee. The chair should support the thighs while leaving two to three centimetres of clearance behind the knees to the seat edge.

Chair quality varies sharply. Stiftung Warentest, the German consumer testing foundation, has examined 18 models since 2024, nine of them in its 2026 round, and gave an unrestricted recommendation to just five. The top scorers, all rated 2.3, were the Dauphin @Just Evo Operator AJ 4876 at 449 euros, the Interstuhl Backforce V Plus at 499 euros and the Recaro NXT Essential Premium at 629 euros. Other models drew criticism for broken armrests, tipping hazards, problematic plasticisers and elevated formaldehyde levels.

Sitting is not the villain — stillness is

Static posture loads the body heavily. EU-OSHA data show that upright sitting without back support raises pressure on the lumbar discs to 140 percent of the standing level; leaning forward pushes it to 190 percent. A chief physician in orthopaedics notes that sitting places 1.5 times the pressure on the lumbar spine, and a slumped posture two to three times as much.

Standing all day is no cure either. Research from the University of Sydney shows that prolonged standing at work can increase the risk of circulatory problems, varicose veins and muscle tension. A physiotherapist with Aktion Gesunder Rücken (the Campaign for Healthy Backs) therefore recommends the 25/50/25 rule: within each hour, sit for 30 minutes, stand for 15 and spend 15 in motion.

Better furniture has limits

Scientific analysis tempers expectations that buying new furniture alone will fix things. A meta-analysis by University of Sydney researchers, published in the Cochrane Database of Systematic Reviews, pooled 20 clinical trials with 2,478 participants suffering work-related musculoskeletal disorders. In the short term it found little to no demonstrable benefit from ergonomic interventions on pain, ability to work or recovery.

Beyond three months, eight studies covering 873 participants hinted only at slight improvement, with moderate to low certainty in the results.

That is why specialists stress active movement. A Macquarie University study suggests a 30-minute walk can help against back pain, while 7,000 steps a day benefits general fitness. The World Health Organization classifies around 90 percent of lower-back pain cases as non-specific, which is why medication is not intended as first-line treatment.