Comparison of accommodative adaptation using laser and infra-red optometers.
Previous investigations have reported differences in the rate of decay of accommodative adaptation depending on the form of optometer used to assess dark-focus (DF). This study has used both laser and infra-red optometers to measure pre- and post-task values of DF in 10 subjects. DF was assessed before and immediately after an 8 min near-vision task performed at the subjective near-point of accommodation. Examination of the data from the two optometers revealed significant differences in both magnitude and distribution of pre-task DF. Additionally variations in the post- to pre-task shift in DF were observed between the two methods of assessment. Using the laser optometer, six subjects exhibited positive adaptation following the near-task which was not apparent with the infra-red optometer. The data suggest that both instruments may not be sampling open-loop accommodation; the laser optometer is particularly vulnerable to extraneous influences.
Rosenfield
M
M
Schnurmacher Institute for Vision Research, SUNY/State College of Optometry, NY 10010.
D000065:Accommodation, Ocular / Q000502:physiology*; D000221:Adaptation, Ocular / Q000502:physiology*; D000328:Adult; D005260:Female; D006801:Humans; D007259:Infrared Rays; D007834:Lasers; D008297:Male; D012029:Refraction, Ocular / Q000295:instrumentation*; D014792:Visual Acuity