Need for the study Virtual reality HMDs are being developed and marketed ingrowing numbers and its most commonly associated with entertainmentapplications (e.g. virtual-reality rides and computer games) other applicationswhich are used very widely nowadays specially by young age group. This increasesthe worries about possible harmful effects on the human eye after using virtualreality HMDs. There is lack of knowledge on the influences of uses of virtualreality HMDs on the ocular parameter and there is no study regarding the effectof virtual reality HMD on tear film secretion, stability, and ocular surfaceevaluation), blinking rate and ocular surface temperature. Literature review: Author, year Journal title Outcome Results Conclusion Limitation The visual effects of head-mounted display (HMD) are not distinguishable from those of desk-top computer display Eli Peli TBU time and vergence parametes were measured after use of head-mounted display (HMD) 1-TBU : decrease in TBU times (average 6–7 s) 2- vergence : There was a significant main effect of time-oftest for the near lateral vergence break and recovery ranges, indicating a small reduction The mean change was 2 prism D in all conditions. There is reduction in tear backup time and vergence parameters Study have been reported the effect of virtual reality HMDs on the users eye parameters such as binocular and visual comfort, however, there are limited study about the effect of virtual reality HMDs on the tear film (secretion and stability), and blinking rate and ocular surface temperature were not reported in these studies.
Aim of the studyThis study aimed to investigate the effect of virtualreality HMDs pre and post on binocular vision function, tear film, blinkingrate and ocular surface temperature after use it for period of time. Objectiveof the study 1- To assess the binocular vision parameters : Fusionalvengeance (Negative Fusional vergence , Positive Fusional vergence ) near pre and post use2- To assess the tear film parameters :1- Tear secretion (Schirmer I and Schirmer II) preand post use2- Tear film stability ( invasive and non-invasive tearbreak-up time ) pre and post use3- To check the blinking rate pre and postuse4- To check the ocular surface temperature preand post use