Impact of Inter-Screen Distance on Visual Clarity in Fixed-Optical System HMD Device

Inter-pupillary distance (IPD), the distance between the pupils of the eyes, varies among individuals and is a crucial human factor in ensuring clear image perception in head-mounted display environments. Although adjusting the lens distance within the device to match the IPD would be ideal, it is impractical due to cost and design constraints. Therefore, our study proposed to adjust the inter-screen distance (ISD) instead, and investigated the conditions for clear image. Our results revealed there exists conditions of ISD that forms a clear image, However, the range is not dependent IPD and varies among individuals, potentially influenced by the user's ocular movements. Additionally, we found that the ISD range for clear image becomes narrower for smaller objects. These findings suggest the importance of providing customized ISD conditions for each user to ensure optimal image.