For opticians, optometrists and ophthalmologistsYour smart
lens calculator
Distance glasses, contact lenses or prismatic correction: 28 calculators, free and without sign-up.
All 28 calculators
Sorted by field. In every calculator, the sidebar takes you to all the others.
Spectacle Optics
- Vertex ConversionConverts correction values when changing the back vertex distance.
- Cylinder ConversionConverts refraction values between plus-cylinder and minus-cylinder notation.
- Combine PrismsAdds two prisms vectorially to find the resultant prism.
- Resolve PrismsResolves a prism into its horizontal and vertical components.
- PMZ - Formula CaseConverts PMZ prisms to formula case order values for spectacle lenses.
- Prism DistributionOptimally distributes prisms between both eyes to minimize lens thickness.
- Tilted LensCalculates correction values for face-form and pantoscopic tilt.
- Spectacle MagnificationDetermines spectacle lens magnification from shape and power factors.
- Prism ImbalanceCalculates the slab-off prism needed for anisometropia.
- Centering ToleranceChecks spectacle lens centration per ANSI Z80.1-2010 standard.
Contact Lenses
- Soft CLsCalculates order parameters for toric soft lenses using the LARS rule.
- RGP Initial FitSuggests the first rigid trial lens from corneal radii and refraction.
- RGP FittingDetermines order parameters for rigid gas-permeable lenses on material change.
- RGP ConversionConverts RGP lens power between air-side and eye-side values.
- Sagittal HeightCalculates sagittal height and eccentricity for multi-curve contact lenses.
- Draw lensDraws the lens geometry to scale as a cross-section.
- Fluo simulationSimulates the fluorescein pattern of a rigid lens.
- Fluo AnalysisAnalyses a fluo photo for bearing and edge clearance.
Myopia Management
Low Vision Aids
Visual Optics
- Cross CylindersCombines two sphero-cylindrical lenses with different axis orientations.
- ConvergenceCalculates the convergence angle for a given working distance and PD.
- Radius ConverterConverts between radius (mm) and power (D) for corneal parameters.
- Corneal AsphericityConverts between Q-value, eccentricity and shape factor of the cornea.
- AC/A RatioCalculates the AC/A ratio using the calculated and gradient methods.
Good vision is no accident.
With the right tool, contact lenses can be fitted more precisely, errors avoided and unnecessary follow-ups prevented. That is why we turned our long practical experience into a tool that is there for you around the clock – in the workshop, in daily practice or in training.
Built by practitioners
Two experienced opticians and optometrists with many years of practice.
Andreas Polzer
Optician and optometrist from Landshut
Georg Scheuerer
Optician and optometrist from Taufkirchen
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Want to integrate the lens calculator into your practice software? You can request an API key by email. hallo@bessersehen.la