TY - JOUR
T1 - Continuous measurement of accommodation in human factor applications
AU - Wolffsohn, J.S.
AU - Hunt, O.A.
AU - Gilmartin, B.
PY - 2002/9
Y1 - 2002/9
N2 - It has long been sought to measure ocular accommodation continuously in human factor applications such as driving or flying. Open-field autorefractors such as the Canon R-1 could be converted to allow continuous, objective recording, but steady eye fixation and head immobilisation were essential for the measurements to be valid. Image analysis techniques utilised by newer open-view autorefractors such as the Shin-Nippon SRW-5000 are more tolerant to head and eye movements, but perhaps the technique with the greatest potential for the measurement of accommodation in human factor applications is photoretinoscopy. This paper examines the development of techniques for high temporal measurements of accommodation and reports on the tolerance of one such recent commercial instrument, the PowerRefractor (PlusOptiX). The instrument was found to be tolerant to eye movements from the optical axis of the instrument (∼0.50 DS change in apparent accommodation with gaze 25° eccentric to the optical axis), longitudinal head movement (<0.25 DS from 8 cm towards and 20 cm away from the correct photorefractor to eye distance) and changes in background illuminance (<0.25 DS from 0.5 to 20 cd m-2 target luminance). The PowerRefractor also quantifies the direction of gaze and pupil size, but is unable to take measurements with small pupils <3.7 ±1.0 mm. © 2002 The College of Optometrists.
AB - It has long been sought to measure ocular accommodation continuously in human factor applications such as driving or flying. Open-field autorefractors such as the Canon R-1 could be converted to allow continuous, objective recording, but steady eye fixation and head immobilisation were essential for the measurements to be valid. Image analysis techniques utilised by newer open-view autorefractors such as the Shin-Nippon SRW-5000 are more tolerant to head and eye movements, but perhaps the technique with the greatest potential for the measurement of accommodation in human factor applications is photoretinoscopy. This paper examines the development of techniques for high temporal measurements of accommodation and reports on the tolerance of one such recent commercial instrument, the PowerRefractor (PlusOptiX). The instrument was found to be tolerant to eye movements from the optical axis of the instrument (∼0.50 DS change in apparent accommodation with gaze 25° eccentric to the optical axis), longitudinal head movement (<0.25 DS from 8 cm towards and 20 cm away from the correct photorefractor to eye distance) and changes in background illuminance (<0.25 DS from 0.5 to 20 cd m-2 target luminance). The PowerRefractor also quantifies the direction of gaze and pupil size, but is unable to take measurements with small pupils <3.7 ±1.0 mm. © 2002 The College of Optometrists.
KW - autorefractors
KW - continuous recording
KW - human factors
KW - ocular accommodation
UR - http://www.scopus.com/inward/record.url?scp=0036729202&partnerID=8YFLogxK
UR - http://onlinelibrary.wiley.com/doi/10.1046/j.1475-1313.2002.00050.x/abstract
U2 - 10.1046/j.1475-1313.2002.00050.x
DO - 10.1046/j.1475-1313.2002.00050.x
M3 - Article
C2 - 12358306
SN - 1475-1313
VL - 22
SP - 380
EP - 384
JO - Ophthalmic and Physiological Optics
JF - Ophthalmic and Physiological Optics
IS - 5
ER -