We present a varifocal system for generating consistent accommodation cues and providing prescription correction in Virtual Reality Head-Mounted Displays (VR HMDs). The proposed approach mitigates the Vergence-Accommodation Conflict (VAC), a fundamental cause of discomfort in today’s VR, and eliminates the need for corrective eyeglasses inside head-mounted displays. We augment traditional objective lenses with a focus-adjustable optical system based on Alvarez lenses, and demonstrate a proof-of-concept integration into a commercial mobile VR headset. This paves the way to lighter, thinner, and more comfortable headsets, enabling the prolonged use of VR with minimal visual discomfort.
Adjustable lens technology has the potential to improve Head Mounted Displays (HMDs) through style and comfort by providing optical prescription correction and focussing mechanisms integrated within the HMD. It can also reduce simulator sickness and user experience of 3D through resolution of Vergence Accommodation Conflict, and age-related user problems (presbyopia). We review the available technology and the design constraints to show how a fluid filled lens may be appropriate for AR and MR, and an Alvarez lens may be appropriate for VR.