Blueprint: Vision Screening with a Smartphone — Implementation Specification

Implementation specification for the smartphone vision screening protocol: distance acuity at a measured 2 m against the 6/12 referral boundary, a 1.2 mm pinhole step that assigns a probable refractive cause from 1.19 D, and phone photorefraction excluded from the pathway below its 3.33 D dead zone, with modelled sensitivity 95.18 percent and specificity 98.82 percent. DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT, NOT CLINICALLY TESTED Blueprint for the protocol published as DOI 10.5281/zenodo.24108713.