[Magnetic field on the deranged accommodation of visual detector terminal operators].
The effects of magnetic fields on the accommodation of operators engaged in visual display terminals (VDT) who complained of asthenopia and proved to have some abnormalities in the semistastic properties of accommodation were examined. Before and after loading a magnetic field of 400 Gauss or 2,000 Gauss on the eye, the quasistatic properties of accommodation were measured and compared. The quasistastic properties analyzed in this experiment were the maximum amplitude of accommodation and the gradient of accommodation that means a ratio of accommodative response to accommodative stimulus. Both factors were statistically improved in a dose dependent manner after loading the magnetic field, i.e. 2,000 Gauss was more effective than 400 Gauss concerning the improvement of accommodation. To exclude a psychogenic effects, simulated loading by a placebo which was an imitation magnet which did not produce a magnetic field was also applied to the patients, but no improvement was detected. Normal persons who were examined as controls showed no statistical change in the semistastic properties of accommodation after loading of the magnetic field. After examination of the semistatic properties of accommodation, refraction was also estimated by an autorefractometer, but no change was detected in either patients or controls. The magnetic field seemed definitely to have effects on the functionally involved accommodative system.
Edagawa
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D000065:Accommodation, Ocular; D000328:Adult; D001248:Asthenopia / Q000209:etiology / Q000503:physiopathology; D003199:Computer Systems; D004574:Electromagnetic Fields / Q000009:adverse effects*; D055590:Electromagnetic Phenomena / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000209:etiology / Q000503:physiopathology