VisionR: Web-Based Eye Viewing Distance Monitoring System Using HC-SR04 Ultrasonic Sensor for Computer Vision Syndrome Prevention

Abstract

The global surge in digital screen dependency has escalated Computer Vision Syndrome (CVS) into a critical occupational hazard, inflicting severe losses in workplace productivity and a substantial financial drain on ophthalmic healthcare expenditures. Affecting an estimated 50–90% of digital screen users worldwide, this condition induces chronic visual discomfort and cognitive decline, yet accessible, affordable, and privacy-preserving preventive monitoring solutions remain critically underserved. To mitigate these widespread ergonomic risks, VisionR was developed as a web-based eye-to-screen viewing distance monitoring platform that integrates an ESP32 microcontroller with an HC-SR04 ultrasonic sensor, offering a completely camera-free, privacy-preserving alternative to existing tracking modalities. The system wirelessly transmits distance data to Firebase and visualizes it via an interactive web dashboard featuring real-time distance indicators, historical trend charts, and a multi-tiered alert mechanism grounded in clinical ergonomic thresholds. Functional validation demonstrated an exceptional sensor accuracy of 98.6% with a minimal average deviation of 0.6 cm across a 30–100 cm range. Furthermore, a user evaluation involving 30 respondents via an adapted System Usability Scale (SUS) and a purpose-developed clinical benefit questionnaire yielded high acceptance: 90% of users validated the accuracy of the distance feedback, 93% expressed complete privacy satisfaction, and 83% reported a willingness to use the system daily, achieving a mean satisfaction score of 4.2/5.0. A structured gap analysis using the PIECES framework verified that VisionR successfully resolves the critical limitations of privacy, accessibility, and analytics inherent in current solutions through a non-invasive, low-cost, and browser-accessible architecture, presenting a highly scalable digital ergonomic intervention tailored for diverse global work and study environments