OpiCalc Logo

OpiCalc

805 Clinical Tools

Logo
OpiCalc
AMD Severity ScaleAstigmatism AssistantDiabetic Retinopathy RiskDiopter <-> RadiusGlaucoma ProgressionGlaucoma Risk (OHTS)Graves CASIOP Correction (CCT)ISNT RuleLogMAR <-> SnellenMRD AssessmentSUN Uveitis GradingVertex Distance
OpiCalc Logo

OpiCalc

Open-access clinical infrastructure. Built to the standard every clinician deserves — fast, private, and free.

Zero data stored
Always free
Our mission & transparency

Get in Touch

Tool request, clinical feedback, or partnership inquiry — we read everything.

WhatsApp feedback
Email us
Partnership inquiry

© 2026 OpiCalc • Calculated Care

MissionPrivacyTerms

MRD Assessment

MRD-1 (Upper Lid)

mm

MRD-2 (Lower Lid)

mm
Guidelines & Evidence

Clinical Details

Section 1

Formula & Logic

Definitions

MRD-1: Distance from the upper eyelid margin to the corneal light reflex (Normal: 4-5 mm)
MRD-2: Distance from the corneal light reflex to the lower eyelid margin (Normal: 5 mm)
Palpebral Fissure (PF): MRD-1 + MRD-2

Clinical Interpretation

MRD-1 < 4mm typically defines ptosis. Low MRD-1 with a high MRD-2 may suggest eyelid retraction (e.g., in Graves disease).

Last Comprehensive Review: 2026

Related Ophthalmology Tools

AMD Severity Scale
Astigmatism Assistant
Diabetic Retinopathy Risk
Diopter <-> Radius
Glaucoma Progression
Glaucoma Risk
Graves CAS
IOP Correction
ISNT Rule
LogMAR <-> Snellen
Have feedback about this calculator?Let us know.