Smartphone-based Utility of the Vestibulo-ocular Reflex

The goal of this observational study is to evaluate whether a novel smartphone-based (mHealth) application can accurately assess gaze stability and vestibulo-ocular reflex (VOR) function in adults with vestibular dysfunction. This pilot clinical ststudy includes adult participants with and without unilateral peripheral vestibular dysfunction to determine the feasibility of a mobile-based assessment of gaze stabilization. The main questions it aims to answer are: 1. Can a prototype mHealth application accurately measure outcomes associated with standard dynamic gaze stabilization tests (e.g., static visual acuity, perception time, and maximal head velocity measurements)? 2. How well does a prototype mHealth application identify patients with unilateral peripheral vestibular dysfunction when compared to healthy volunteers? 3. Does a prototype mHealth application differ in identifying patients with unilateral peripheral vestibular dysfunction when compared to a commercially-available computer system that uses a gold-standard head-mounted sensor for gaze stabilization testing (GST)? Participants will: Perform the well-established GST protocol using a commercially-available computer system that uses a gold-standard head-mounted sensor Perform the well-established GST protocol a novel mHealth application The following outcomes will be measured: 1. Standard visual acuity (SVA): The smallest readable target based on the user's best-aided vision 2. A perception time test (PTT): The shortest time a target can be accurately identified 3. A dynamic gaze stability test (GST): The maximal head velocity at which a patient can accurately identify the orientation of a presented visual target This pilot clinical study will provide evidence to further support the use of mobile technology as a low-cost, accessible alternative for vestibular function assessment, particularly for patients in resource-limited settings.