5 Ophthalmology Calculators
All scales are based on peer-reviewed sources (AAO PPP, DEWS II, IMI consensus). For self-education only — final diagnosis and treatment require an in-person ophthalmology evaluation.
OSDI · Ocular Surface Disease Index
OSDI is the most-used dry-eye symptom questionnaire — light, wind, screens. Original is 12 items; this site uses a simplified 6-item version.
DEQ-5 · 5-item Dry-Eye Screen
DEQ-5 is a 5-item dry-eye questionnaire. ≥6 → likely DED; ≥12 → screen for Sjögren (anti-SSA/Ro).
Snellen ↔ LogMAR Conversion
LogMAR = log10(1 ÷ Snellen decimal). Clinical trials use LogMAR (additive). WHO legal blindness: Snellen ≤ 20/400 (0.05 / LogMAR ≥ 1.30).
Spherical Equivalent (SE)
SE = sphere + cyl/2. Standard tool for myopia tracking. ≤ -6.00 D = high myopia, increased risk of retinal detachment and myopic maculopathy.
Floater Red-Flag Self-Check
Most floaters are benign vitreous opacities — but sudden showers + flashes + field defects may signal retinal tear/detachment. List based on AAO PVD PPP 2023.
All calculators on this page are self-education tools and cannot replace an in-person ophthalmology evaluation. OSDI / DEQ-5 are screening — positives need Schirmer, TBUT, ocular surface staining, tear osmolarity. SE and VA conversion are computational tools, not diagnostic. Floater red-flags are triage guidance only. Per Taiwan Medical Care Act §85-86 and Physicians Act §17, individual outcomes vary; no result is guaranteed.