Influence of Static Visual Acuity, Tachistoscopic Vision and Eye Movements on Dynamic Visual Acuity

Abstract

Purpose: The purpose of this study was to investigate the relationship between dynamic visual acuity and static visual acuity, tachistoscopic vision, or eye movements to determine the characteristics of dynamic visual acuity. Methods: The experiment was performed on 40 subjects. Dynamic visual acuity was measured for subjects to recognize the direction of target which was oriented in four directions(top, bottom, right, left) and moved horizontally. Dynamic visual acuity was specified as the maximum angular velocity that subjects can resolve an orientation of a snellen E target projected onto the screen. Static visual acuity was assessed using the logMAR chart at 4 m; high-contrast(100%) and low-contrast(10%) static visual acuity were evaluated according to the contrast between optotypes and a background of the chart respectively. Tachistoscopic vision was evaluated by a five-number-digit target which was presented for 14 and 7 msec. A remote eye-tracking device recorded fixation and saccadic eye movements while subjects were reading the NYSOA King-Devick test. Results: High-contrast and low-contrast static visual acuity were significantly correlated with dynamic visual acuity(high-contrast visual acuity: r=-0.43, p=0.01, low-contrast visual acuity: r= -0.40, p=0.01). Dynamic visual acuity showed no correlation both with tachistoscopic vision (r= -0.29, p=0.07) and tachistoscopic vision when reduced influence of the visual memory during the tachistoscopic vision test (r=-0.10, p=0.57). Fixation and saccadic eye movements were not correlated with dynamic visual acuity (fixation counts: r=0.07, p=0.65, fixation duration: r=0.27, p=0.10, saccade counts: r=0.02, p=0.93, saccade duration: r=0.01, p=0.98, saccade amplitude: r= 0.22. p=0.18, saccadic velocity: r=0.23, p=0.15). The most influential factor for dynamic visual acuity was high-contrast visual acuity in a multiple regression analysis(β=-0.43, p=0.01). Conclusion: These results suggest that the dynamic visual acuity is related with vision and visual quality based on static visual acuity. High-contrast visual acuity is the most effective factor on dynamic visual acuity among static visual acuity, tachistoscopic vision and eye movements. However, It is considered that further investigations need to analyze the correlation between dynamic visual acuity and tachistoscopic vision or eye movements.