The Effects of Visual Display Distance on Eye Accommodation, Head Posture, and Vision and Neck Symptoms

In: Human factors: the journal of the Human Factors Society, Band 49, Heft 5, S. 830-838

Abstract

Objective: Determine the effects of display viewing distance on both the visual and musculoskeletal systems while the text height is held constant across viewing distances. Background: The distance from the eyes to a computer display may affect visual and neck comfort. If the angular size of the characters remains the same, it is recommended that the display be placed at a farther viewing distance (e.g., 70—100 cm). However, in common usage, the character sizes are not adjusted based on viewing distance. Method: Participants under the age of 35 years ( N = 24) performed visually demanding tasks using a computer display for 2 hr each at three viewing distances (mean: 52.4, 73.0, and 85.3 cm) while torso and head posture were tracked. At the end of each task, eye accommodation was measured and symptoms were recorded. Results: The near distance was associated with significantly less blurred vision, less dry or irritated eyes, less headache, and improved convergence recovery when compared with the middle and far distances. Participants moved their torsos and heads closer to the monitor at the far distance. Conclusion: If the computer screen character sizes are close to the limits of visual acuity, it is recommended that the computer monitor be positioned between the near (52 cm) and middle (73 cm) distance from the eyes. Application: The location of a computer display should take into account the size of the characters on the screen and the visual acuity of the user.