[Asthenoptic complaints in conjunction with illumination by gas discharge lamps]

Asthenopic complaints frequently occur when visual requirements are high in conjunction with illumination by gas discharge lamps. Four causes should be considered: level of the vision task, quality of light (spectral distribution, fluorescent flicker), quality of illumination, individual characteristics of the affected subject. Of 3000 patients, 58% had asthenopic complaints when exposed to gas discharge lamps. The number of females was twice that of males. The subjects affected were predominantly women, aged 20-30 years, who exhibited autonomic lability. Also, they showed reduced concentration power, diminished binocular and stereo vision, and more than normal photic driving findings in the EEG. Fluorescent flicker exerted no influence on elementary visual power, concentration power visuomotor performance, or optical reaction time. It did have an effect on dynamic visual acuity, flicker frequency, blinking rate, and the demands experienced. Fluorescent flicker should be reduced, e.g., by three-phase connection or electronic ballasts. Correcting the binocular vision and reducing the individual glare sensitivity are approaches indicated for individual therapy.