Can a smartphone app replace paper for eye exams in clinical trials?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

90 adult participants (≈180 eyes) with the following BCVA levels, will be included: * 30 participants (33%) in the normal/near-normal BCVA range (≤0.3 logMAR ≥70 letters); ≈20/40 or better); * 30 participants (33%) with mid-range BCVA (0.4-0.9 logMAR (36-69 letters); 20/50 to 20/200) * 30 participants (33%) with low vision BCVA (≥ 1.0 logMAR (≤35 letters); worse than 20/200) including off-chart acuities using protocol low-vision procedures). Inclusion Criteria: * Adults ≥18 years old * Able and willing to provide written informed consent * Capable of performing BCVA testing procedures according to study requirements * All BCVA ranges are eligible, including off-chart acuities (e.g., count fingers, hand motion, light perception) irrespective of the presence or absence of ocular disease. Exclusion Criteria: * Any condition preventing reliable completion of BCVA testing (e.g., severe cognitive impairment, language barriers) * Inability or unwillingness to comply with study requirements * Non-ophthalmic condition that precludes safe or reliable testing (e.g., immediate post-operative systemic status preventing cooperation). * Any circumstance that, in the investigator's opinion, makes the eye/participant unsuitable for accurate BCVA testing or for completing both data-capture methods during the same visit. Number of Sites: 2 ophthalmic clinical research centers Portugal) Number of Countries: Portugal Number of Visits: One study visit per participant Duration: 2 months Participants will undergo BCVA testing at a single visit using both paper-based recording and electronic capture with Acuvera Capture. Testing order will be randomized to minimize bias. Paper data will be inserted by the examiners or study coordinator into the study eCRF. Electronic capture data will be exported directly from the app.