title: Steady-state accommodation response and VDT screen conditions.
abstract: Steady-state accommodation response was measured for seven different visual display terminal (VDT) screen conditions and a hard-copy control condition. The screen conditions included variations in screen polarity, contrast and chromatic characteristics of the text and background. Accommodation response was measured for seven young subjects using a free-space infrared optometer, the Canon Autoref R-1. The accommodation response was measured every 1.3 s over a period of 60 s for each test condition, and both the mean and standard deviation of the responses were derived. A small but significantly higher accommodation response was found for hard copy, blue-on-red and red-on-blue screen conditions compared with white-on-black, green-on-black and black-on-white screen conditions. Screen polarity and contrast had little effect on accommodation response for the black-and-white screen conditions. The variability of accommodation response showed little difference between test conditions. For short-term VDT screen viewing, the accommodation response appears to be relatively accurate and stable across a wide range of screen conditions.
authors.affiliation: Centre for Eye Research, School of Optometry, Queensland University of Technology, Locked Bag No. 2, Red Hill, Queensland, Australia, 4059.
authors.forename: M
authors.initials: M
authors.lastname: Collins
authors.forename: B
authors.initials: B
authors.lastname: Davis
authors.forename: A
authors.initials: A
authors.lastname: Goode