With the help of augmented reality (AR) and virtual reality (VR) systems, users can receive information and connect with each other via near-eye displays (NEDs). However, several challenges need to be addressed, and the optics are the major bottlenecks. Users wearing current NEDs typically suffer from vergence-accommodation conflict (VAC). Furthermore, people with refractive errors need a pair of prescription lenses to clearly see the virtual image and/or environment. Hence, VAC-free AR/VR systems with vision correction functions should be developed. Furthermore, the AR/VR systems must be designed with slim form factors. Liquid crystal (LC) optical elements with a thin form factor have been demonstrated for light modulation in versatile optical systems; thus, LC-based solutions have been proposed for AR/VR systems in the past decade. Herein, we provide a comprehensive review on the existing literature on LC-based optical systems and suggest possible solutions to realize a better NED system. This review provides an overview of the state-of-the-art progress of LC optics in AR and VR systems. It focuses on the fundamental optics of NEDs, origins of VAC and current LC-based solutions, LC lenses for vision correction function, and the guidelines for solving the two aforementioned challenges using LC lenses.

在增强现实 (AR) 和虚拟现实 (VR) 系统的帮助下，用户可以通过近眼显示器 (NED) 接收信息并相互联系。然而，有几个挑战需要解决，光学是主要的瓶颈。佩戴当前 NED 的用户通常会遭受聚散调节冲突 (VAC)。此外，屈光不正的人需要一副处方镜片才能清楚地看到虚拟图像和/或环境。因此，应开发具有视力矫正功能的无VAC AR/VR系统。此外，AR/VR 系统必须设计成纤薄的外形。具有薄外形的液晶 (LC) 光学元件已被证明可用于通用光学系统中的光调制；因此，在过去十年中，已经为 AR/VR 系统提出了基于 LC 的解决方案。在此处，我们对基于 LC 的光学系统的现有文献进行了全面回顾，并提出了实现更好 NED 系统的可能解决方案。本综述概述了 LC 光学在 AR 和 VR 系统中的最新进展。它侧重于 NED 的基本光学、VAC 的起源和当前基于 LC 的解决方案、用于视力矫正功能的 LC 镜头，以及使用 LC 镜头解决上述两个挑战的指南。