ODReferenceOptometry Reference & Contact Lens Calculators

Explore Main Sections

Contact lens parameters, calculators, ophthalmic medication tables, and chairside reference values.

• Contacts

  Contacts

  Lens parameters & calculators

  • Brand portfolios
  • Lenses by modality
  • Conversion tools
• Medications

  Medications

  Ophthalmic drug tables

  • Drug classes & indications
  • Dosing & safety notes
  • Brand and generic options
• Reference

  Reference

  Optometry norms & tests

  • Visual & BV norms
  • Dry eye & IOP references
  • Chairside clinical charts

Popular Tools

Quick links to commonly used calculators.

• Contact Lens Calculator

  Convert spectacle prescriptions to contact lens powers and spherical equivalent.

• Plus/Minus Cylinder Converter

  Transpose prescriptions between plus and minus cylinder formats.

• Cross-Cylinder Calculator

  Toric refinement, Rx combination, and power cross.

• RGP Lens Calculator

  Support RGP fittings with base curve selection, power changes, and more.

• Radius/Base Curve Converter

  Convert between base curve radius (mm) and diopters (D) for contact lens fits.

• Vertex Distance Calculator

  Check vertexing correction for varying spectacle prescriptions.

Designed for Real-World Optometric Practice

Tools and content structured to fit the way you actually work in clinic.

• Clinical guides & parameter tables

  Concise guides for contact lenses, medications, and key reference values built for quick chairside look-ups.

• Purpose-built calculators

  Tools for contact lens powers, cylinder transposition, vertex distance, RGP design, and more to streamline routine math.

• Fast, intuitive navigation

  Organized around contacts, medications, and reference so you can reach the right tool quickly during a busy clinic day.

• Continuously maintained content

  Updated as lenses launch, drug options change, and evidence-based ranges evolve so chairside info stays current.

• Built by and for clinicians

  Designed to mirror real-world workflows with clarity, practicality, and evidence-informed ranges you can trust.

• Open access on any device

  Use ODReference on desktop, tablet, or phone, without logins or paywalls slowing down patient care.

Used by Eye Care Professionals Worldwide

Quickly access trustworthy information and tools for everyday practice.

Users

150k+

Visitor Countries

150+

Data Entries

500+

Cost

Free