  This study comprehensively evaluates tuning methods for autofocal glasses
using virtual reality (VR), addressing the challenge of presbyopia. With aging,
presbyopia diminishes the eye's ability to focus on nearby objects, impacting
the quality of life for billions. Autofocals, employing focus-tunable lenses,
dynamically adjust optical power for each fixation, promising a more natural
visual experience than traditional bifocal or multifocal lenses. Our research
contrasts the most common tuning methods - manual, gaze-based, and vergence -
within a VR setup to mimic real-world scenarios. Utilizing the XTAL VR headset
equipped with eye-tracking, the study replicated autofocal scenarios, measuring
performance and usability through psychophysical tasks and NASA TLX surveys.
Results show varying strengths and weaknesses across methods, with gaze control
excelling in precision but not necessarily comfort and manual control providing
stability and predictability. The findings guide the selection of tuning
methods based on task requirements and user preferences, highlighting a balance
between precision and ease of use.
