Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, Massachusetts.
Optom Vis Sci. 2020 Aug;97(8):573-582. doi: 10.1097/OPX.0000000000001541.
To judge the feasibility of virtual reality (VR) headsets for vision testing and treatment of binocular vision disorders and low vision, angular resolution (logMAR) and field of view must be known and may not be reliably provided. This is the first study to measure the limitations of VR systems for eye care applications.
This study aimed to measure, in a sample of VR headsets, eye-to-screen distance and other physical and optical characteristics needed to calculate minimum angular resolution in logMAR and field of view in determining feasibility for vision applications.
Eye-to-screen distance was measured, and logMAR, field of view, and maximum convergence demand were calculated for two standalone VR devices, Oculus Rift DK2 and HTC Vive, and, for four smartphone VR headsets, Zeiss VR1, Samsung Gear VR, VR Box, and SunnyPeak, each paired with four high-resolution smartphones, Samsung Galaxy S7/S8, iPhone X, and LG VR30.
On average, the smallest letter that could be displayed in VR was 0.41 ± 0.09 (20/51), ranging from 0.59 (20/78) in the DK2 to 0.28 (20/39) in VR Box with S7. Mean field of view was 50.2 ± 4.8°, ranging from 39.6° in the VR Box with S7 to 55° in the HTC Vive. The mean field of view when used as a low vision aid was 23.0° and 12.7° for 2.2× and 4×, respectively. The mean maximum near convergence demand produced for a 60-mm interpupillary distance was 38.6 ± 10.1Δ.
The minimum angular resolution in logMAR of current VR technology is insufficient for visual acuity testing and may be insufficient for standalone treatment of amblyopia. Field of view during movie watching or gaming is about half that reported by manufacturers but adequate for some types of visual field testing. Use for vergence testing and training is a concern for headsets with long eye-to-screen distance or interpupillary distances <60 mm.
为了判断虚拟现实（VR）头显在双眼视功能障碍和低视力的视觉测试和治疗中的可行性，必须了解并可能无法可靠提供角分辨率（logMAR）和视野。这是第一项测量 VR 系统在眼保健应用中的局限性的研究。
本研究旨在测量一系列 VR 头显中的眼屏距离和其他物理及光学特性，以计算 logMAR 中的最小角分辨率和视野中的视野，从而确定视觉应用的可行性。
测量眼屏距离，并计算两个独立 VR 设备（Oculus Rift DK2 和 HTC Vive）以及四个智能手机 VR 头显（Zeiss VR1、Samsung Gear VR、VR Box 和 SunnyPeak）的 logMAR、视野和最大聚散需求，每个头显都与四部高分辨率智能手机（Samsung Galaxy S7/S8、iPhone X 和 LG VR30）配对。
平均而言，VR 中可以显示的最小字母为 0.41 ± 0.09（20/51），范围从 DK2 中的 0.59（20/78）到 VR Box 与 S7 搭配时的 0.28（20/39）。平均视野为 50.2 ± 4.8°，范围从 VR Box 与 S7 的 39.6°到 HTC Vive 的 55°。作为低视力辅助设备使用时，2.2×和 4×的平均视野分别为 23.0°和 12.7°。对于 60mm 瞳距，平均最大近聚散需求为 38.6 ± 10.1Δ。
当前 VR 技术的 logMAR 最小角分辨率不足以进行视力测试，并且可能不足以单独治疗弱视。观看电影或玩游戏时的视野约为制造商报告的一半，但足以用于某些类型的视野测试。对于眼屏距离较长或瞳距<60mm 的头显，用于聚散测试和训练存在问题。
