Computer Vision Syndrome in Head-Mounted Displays: Spontaneous Eye Blink Rate and Saccades

While computer vision syndrome has been meticulously studied in the context of desktop, laptop, and smart phone displays, there is a gap in the field when it comes to the effects of head mounted displays (HMDs). As the more consumer grade HMDs have become available, it has become important to understand visual strain symptoms associated with their use. This thesis has started to fill that gap by examining one of the known risk factors of dry eye in the context of head mounted display use. To do this, spontaneous eye blink rate was measured across head mounted display and real-world,direct viewing conditions. Head mounted display viewing allows more freedom of movement than desktop, laptop, or phone display viewing. Therefore, gaze shifts were examined to determine whether their corresponding blinks occurred with normal frequency during head-mounted display use. The eye movements of seven participants were recorded as they shifted their gaze between two gaze targets in both direct viewing and virtual reality viewing conditions. Gaze targets were placed at different degrees of separation throughout the experiment. Backward elimination using ANOVAs and F-tests was used to identify significant predictors of blink rate, gaze evoked blinks, inter-blink period, and head rotation. HMD use was found to have no significant effect on blink rate or gaze evoked blinks. Both main and interaction effects of HMD use were found to be significant for head rotation during gaze shifts. Inter-blink period was significantly affected by the interaction between HMD use and angle of separation between gaze targets. A case is made to show this was likely due to the experimental design.