Offline ophthalmology reference and refraction calculator for Pebble Time 2. Browse cup-to-disc ratio, Van Herick grading, gonioscopy landmarks and Shaffer grades, plus refraction tools for transposition, spherical equivalent, optical cross, retinoscopy working-distance correction, and vertex conversion. Designed for fast button and touch navigation and stores no patient data. Educational reference only; not a diagnostic or treatment system.