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.
Dry-eye symptom check (6 questions)
Recall the past week; use the result to describe symptoms to your ophthalmologist.
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
A sudden shower of floaters, flashes, a curtain/field defect or reduced vision requires same-day ophthalmic assessment. This tool cannot rule out a retinal tear or detachment. Long-standing stable floaters without new red flags can be followed according to medical advice.
The floater check cannot exclude a retinal tear or detachment.