Characterizing Visual Acuity in the Use of Head Mounted Displays

In the real world, the sense of sight is dominant for humans, and having a normal vision is essential to perform well in many common tasks. There, ophthalmology has several tools to assess and correct a person's vision. In VR, when wearing an HMD, even a user with normal vision is challenged by additional hurdles that affect the virtual environment's perceptual acuity, negatively impacting their performance in the application task. Display resolution, but also soiled lenses and bad vergence adjustment are examples of possible issues. To better understand and tackle this problem, we provide a study on assessing visual acuity in a VR setup. We conducted an experimental evaluation with users and found out, among other results, that visual acuity in VR is significantly and considerably lower than in real environments. Besides, we found several correlations of the measured acuity and task performance with difficulty adjusting the HMD and use of prescription glasses.