Eye-screen distance monitoring for computer use

Abstract

The extended period many people now spend looking at computer screens is thought to affect eyesight over the long term. In this paper we are concerned with developing and initial evaluation of a wireless camera-based tracking system providing quantitative assessment of computer screen interaction. The system utilizes a stereo camera system and wireless XBee based infrared markers and enables unobtrusive monitoring. Preliminary results indicate that the system is an excellent method of monitoring eye-screen distance. This type of system will enable future studies of eye-screen distance for computer users.

Real-Time Non-Intrusive Assessment of Viewing Distance during Computer Use

“…In effect, interactive tasks (text completion, web searching and game) were associated with shorter viewing distances than the non-interactive video watching task. However, in disagreement with previous research, 19 in which no details on the study sample are provided, no statistically significant difference was found between the text completion and the web browsing tasks. It may be noted that previous research has documented a relationship between the type of task being conducted by computer operators and aspects such as eyeblink 28 rate and visual stress or fatigue.…”

“…The main objective of the present study was to develop an affordable (price of each sensor is about 10$), non-intrusive method to evaluate viewing distance of VDT users and to test it on a sample of participants undertaking four typical computer tasks. Previous efforts at assessing viewing distance in real time in computer users rely on either infrared 19 or ultrasound complex systems, requiring part of the equipment, or at least some markers, to be placed on the forehead of the participants. Therefore, it is believed that these approaches lack operability in that they involve non-trivial installation and configuration, and may interfere with the task being conducted by the participants.…”

“…In addition, viewing distance has been found to depend on such factors as size and resolution of visual stimuli, type of task 19 and screen/text color combination. Thus, for example, given the recommendation of adopting a 3x acuity reserve, 20 a shorter viewing distance is associated with prolonged viewing of texts in fonts of small size.…”

“…On the one hand, Eastwood-Sutherland and Gale developed an infra-red system consisting of a video camera and infra-red LED markers attached to the forehead or the back of the head of VDT operators. 19 With this instrument, the authors were able to document changes in viewing distance with a temporal resolution of 7 Hz, noting a link between the type of activity being conducted and distance, with internet browsing resulting in shorter viewing distances than writing a text. On the other hand, Piccoli and co-workers designed an ultrasound emitter (at 40 KHz), coupled with a receiving sensor placed on the operator's forehead 27 with which the authors reported an accuracy of ±0.5 cm and a maximum temporal resolution of 10 Hz when measuring viewing distance on a sample of VDT users.…”

“…To test whether our sensor was able to detect small changes in viewing distance, measurements were conducted on a sample of participants performing four typical computer tasks. As previous investigators have described an influence of the type of task on viewing distance, 19 this research question was also explored.…”