Concerns about head mounted displays have led to numerous studies about their potential impact on the visual system. Yet, none have investigated if the use of Virtual Reality (VR) Head Mounted Displays with their reduced field of view and visually soliciting visual environment, could reduce the spatial spread of the attentional window. To address this question, we measured the useful field of vision in 16 participants right before playing a VR game for 30 minutes and immediately afterwards. The test involves calculation of a presentation time threshold necessary for efficient perception of a target presented in the centre of the visual field and a target presented in the periphery. The test consists of three subtests with increasing difficulty. Data comparison did not show significant difference between pre-VR and post-VR session (subtest 2: F(1,11) = .7 , p = .44; subtest 3 F(1,11) = .9 , p = .38). However, participants’ performances for central target perception decreased in the most requiring subtest (F(1,11) = 8.1, p = .02). This result suggests that changes in spatial attention could be possible after prolonged VR presentation.
In this paper, we conducted two different studies. Our first study deals with measuring the flickering in HMDs using a selfdeveloped measurement tool. Therefore, we investigated several combinations of software 360° video players and framerates. We found out that only 90 fps content is leading to a ideal and smooth playout without stuttering or black frame insertion. In addition, it should be avoided to playout 360° content at lower framerates, especially 25 and 50 fps. In our second study we investigated the influence of higher framerates of various 360° videos on the perceived quality. Doing so, we conducted a subjective test using 12 expert viewers. The participants watched 30 fps native as well as interpolated 90 fps 360° content, whether we also rendered two contents published along with the paper. We found out that 90 fps is significantly improving the perceived quality. Additionally, we compared the performance of three motion interpolation algorithms. From the results it is visible that motion interpolation can be used in post production to improve the perceived quality.
With the rapid development of mobile Head-Mounted Display (HMD), the problem of visual discomfort and visual fatigue caused by watching Virtual Reality (VR) contents became a crucial concern for consumers and manufacturers, especially given that the casing of mobile HMD keeps the phone at a specified distance from the lenses that is close to the eyes. In this regard, we conducted both subjective and objective measure to evaluate visual discomfort and visual fatigue caused by watching HMD and smartphones. Participants answered Simulator Sickness Questionnaire (SSQ) and went through optometric tests that measure tear break-up time, spherical equivalent, and contrast sensitivity. Experimental results show that HMD causes more eye dryness compared to smartphones.
In a short period of time, virtual reality has taken over the media, tending to promote that idea that it is a new technology. In fact, all started as early as the seventies and eighties, for portable devices (e.g.Head-Mounted Displays) as well as for complex and large devices (CAVEs). In this paper, we try to put these different systems in perspective, and to show the interest of comparing them in an experimental approach.