The scale method as a spectral analysis for accommodative fluctuation.

A scale method of computer analysis was developed as an automatic spectral analysis system of the accommodative fluctuations. The scale approach employed a computer to identify wave peaks. Using this new system. spectral analysis of the fluctuations in accommodation measured by an infrared optometer was performed. Both the power spectrum method and the scale method were used to perform a spectral analysis and a wave form analysis. The spectrum peaks obtained by both methods were virtually coincidental. Twenty sec was adequate for the measuring time examined from the viewpoint of data stability. Fluctuations in accommodation were measured in 17 adult males. The mean peak frequency band range in 18 eyes of the young group was 2.5-3.15 Hz, in contrast to 1.25-1.6 Hz in 16 eyes of the middle-aged group. The newly developed system was considered effective as a criterion for visual load in VDT (visual display terminal) work and other high-level visual tasks.