Assessment of the Effects of Light and Sound Impulses on the Electrical Potential of the Eye and Ocular Muscles

Objective: The aim of this study is to determine the effects of visible light on the electrical potential of the eye and facial/ocular muscles using electrooculography (EOG) and the effects of visible light and sound stimuli electromyography (EMG). We also intend to assess normal human electrical activity by documenting the alteration in EOG and EMG signals. Materials and Methods: The EOG was recorded for 25 healthy individuals (10 women and 15 men) in compliance with the International Society for Clinical Electrophysiology of Vision standards. In addition, visible light and sound stimuli were applied to the test subjects during facial and/or ocular EMGs recording. Further, the data were analysed using SPSS 12.0 statistical program. Results: In normal healthy subjects, the amplitudes of the EOG potential during the dark period (men 0.69±0.09; women 0.67±0.11) were lower than that in the light period (men 1.29±0.18; women 1.35±0.15). The mean values of Arden ratio were 2.06±0.11 and 2.14±0.12 for men and women, respectively. Although visible light stimuli enhanced the EMG signals in the facial and/or ocular EMG, the click sound did not cause significant alteration in the EMG signals. Conclusion: Visible light has been reported to have beneficial effects on the EOG and facial/ocular EMG signals in normal healthy individuals. However, click sound has no effects on the facial/ocular EMG. We therefore propose that facial/ocular EMG and EOG measurements possibly have the potential to diagnose various disorders in clinics.