What is a manufacturer contact lens calculator?
A manufacturer contact lens calculator maps a glasses prescription to that company's trial or ordered lens parameters.
The following tools do that job on live US search results for brand calculator queries:
- CooperVision OptiExpert, which converts eyeglasses prescriptions to corresponding CooperVision contact lens parameters
- ACUVUE simplifit, which combines Johnson & Johnson astigmatism and multifocal calculators into one trial-lens tool
- MyAlcon FittingHub, which converts a spectacle Rx to a sphere, toric, or multifocal Alcon contact lens prescription
Those brand portals, plus ToriTrack and Bausch toric tools, belong on this comparison page. They are not our ontology. We do not output a brand SKU.
How does CooperVision OptiExpert convert a glasses prescription?
OptiExpert converts a patient's eyeglasses prescription to the corresponding CooperVision contact lens parameters.
According to the CooperVision OptiExpert practitioner page, OptiExpert converts that eyeglasses prescription to corresponding contact lens parameters. The same page describes a sphere, toric, multifocal, and toric-multifocal calculator in one, and states that the tool recommends CooperVision toric powers and clariti 1 day multifocal powers. It is available on the App Store, Google Play, and OptiExpert Web. OptiExpert Web also lists oxygen-performance and Efron-grading tabs; those are brand support tools, not conversion optics, and we do not reproduce them.
The same hub footnote states that the calculators aid eye care practitioners and are not a replacement for a professional contact lens fitting. Starting parameters still require trial-lens evaluation.
CooperVision's separate Toric Calculator returns theoretical power as a starting point for any manufacturer's toric lenses, plus specific parameters for CooperVision toric brands. We keep the theoretical-power idea. We do not clone the brand list.
What does ToriTrack calculate that OptiExpert does not?
ToriTrack is CooperVision's cross-cylinder calculator for astigmatic patients.
According to CooperVision’s ToriTrack page, the tool asks for spectacle correction, contact lens correction, and over-refraction in minus-cylinder format, then lens rotation in degrees, rotation direction, and vertex from 10.0 to 15.0 mm in 0.5 mm steps. It returns suggested sphere, cylinder, and axis and rounds to 0.25 D steps. The page limits intended use to educational purposes and links OptiExpert Web.
Independent toric starting power and rotation/over-refraction explanation live on the Toric Contact Lens Calculator. We do not impersonate ToriTrack's product calculator.
What does the ACUVUE simplifit calculator map to?
The ACUVUE simplifit calculator combines Johnson & Johnson's astigmatism and multifocal calculators to identify an ACUVUE trial lens power.
According to the ACUVUE Fitting Calculator, the page title is “ACUVUE Fitting Calculator | Multifocal and Astigmatism | J&J.” The tool includes 12 mm vertex calculation across each power meridian. That 12 mm per-meridian rule is clinical confirmation for our default vertex. It is not a reason to clone an ACUVUE picker.
Johnson & Johnson's on-page disclaimer states that the calculator is for educational and convenience purposes, in conjunction with ACUVUE product labeling, and is not a substitute for independent professional judgment. We agree on the bound. We do not map converted power to an ACUVUE SKU.
Converting a glasses prescription to contact lens parameters is independent of choosing an ACUVUE lens. Isolate vertex on the Contact Lens Vertex Calculator and Distance Chart when you need the 12 mm assumption shown.
How do Alcon FittingHub and Bausch tools map a spectacle Rx?
Alcon FittingHub and Bausch toric tools map a spectacle Rx to that manufacturer's trial or order parameters.
The following table states what those manufacturer pages describe, not a ranking of “best” brands.
| Tool | What it maps to | Independent equivalent |
|---|---|---|
| MyAlcon FittingHub | Spectacle Rx → sphere, toric, or multifocal Alcon Rx; products that fit the patient's parameters are displayed in the web app | Convert starting power; no Alcon product grid |
| FittingHub rounding FAQ | Sphere up to 0.25 D; cylinder down to 0.25 D; axis to 10°; ADD up to 0.25 D; plus-cylinder transposed | Nearest 0.25 D steps; plus-cylinder notation is a prep step, not an Alcon axis grid |
| Bausch + Lomb NL Toric Calculator Tool | Spectacle refraction, lens rotation, back vertex distance (control highlights 12 mm in a 5–20 mm range), theoretical power at the corneal plane, then a lens for order | Starting corneal-plane power; no “lens for order” SKU |
| Bausch + Lomb India Eye Power Calculator | Consumer “convert spectacles power into contact lens power in just 60 seconds” | No speed claim; US ECP starting parameters |
According to MyAlcon FittingHub, the flow is three steps: set country and language preferences, enter the spectacle prescription, then view Alcon products. The web app is free and does not require registration. We name that SKU step. We do not adopt cylinder-down or 10° axis rounding as our engine.
An Alcon Online Toric IOL Calculator that incorporates the Barrett Toric Calculator is cataract planning, not a contact lens calculator. See Wikipedia’s Intraocular lens power calculation page for that surgical job. Multifocal ADD as a starting contact lens parameter, when you need it without an Alcon picker, belongs on the Multifocal Contact Lens Calculator.
How do independent calculators convert spectacle power without a brand grid?
Independent calculators convert spectacle power into starting contact lens parameters without mapping to one manufacturer's SKU grid.
The following table frames independent tools that convert spectacle power without a brand SKU.
| Tool | What it converts | What it does not map |
|---|---|---|
| ODReference Contact Lens Conversion Calculator | Glasses Rx at the trial-frame or phoropter plane into starting soft-lens power: vertex when meridians are at or above about ±4.00 D, optional spherical equivalent after vertex, rounding to manufacturing steps | A brand catalog. Output is a starting point, then on-eye assessment |
| Omni Contact Lens Vertex Calculator | Spectacle-to-cornea vertex (contact-lens vertex = 0); round to nearest 0.25 D; BVD 12 mm as a stated refraction distance | Full conversion workflow, spherical-equivalent choice, or a trial SKU |
| GPLI Toric and Spherical Lens Calculator | GP spherical nomogram at ≤2 D corneal cylinder and GP toric parameters above that; round diopters to 0.25 or 0.01 | Soft-lens brand fit. Empirical GP starting point only |
| contactlenscalculator.net | Consumer glasses-to-contacts conversion with vertex mention | ECP-depth meridians or a starting-parameters disclaimer. That consumer title emphasizes speed; this site does not |
Contact Lens Calc converts that same optical job — vertex-compensated ordered power, optional spherical equivalent when a spherical lens is intended, rounding to 0.25 D steps — and stays manufacturer-agnostic. Verify residual error after the trial lens on the Over-Refraction Calculator for Contact Lens Parameters. Convert this spectacle Rx to starting contact lens parameters on the conversion calculator already named above.
When should you convert independently, then fit and verify on eye?
Convert independently when you need starting contact lens parameters without a brand SKU.
Use this sequence:
- Enter the spectacle refraction as written.
- Calculate vertex-compensated power at a disclosed vertex (default 12 mm unless you set another).
- Fit a starting spherical, toric, or multifocal trial lens on eye.
- Verify power with over-refraction after the trial lens.
Use OptiExpert, simplifit, or FittingHub when the fitter already intends that manufacturer's lens and needs that portfolio's trial SKU. Those tools remain a brand step after independent optics. They do not replace keratometry, topography, slit-lamp assessment, or over-refraction.
Patient aside (Grade 8–9)
CooperVision, ACUVUE, Alcon, and Bausch calculators help a fitter pick that brand's trial lens. A glasses number is still not a contact lens prescription. Converted power is a starting number for a licensed fitter. Don't order lenses from this page.
Not a Rx
Not a prescription / on-eye next step
Starting parameters must be fit and verified on eye. See Starting Contact Lens Parameters Are Not a Prescription. Brand calculators are not a replacement for a professional contact lens fitting either.
Which Contact Lens Calc tools convert starting parameters?
Contact Lens Calc tools convert spectacle prescription to contact lens parameters, then isolate vertex, toric, or inventory as needed.
These related pages sit one click from this comparison:
- Contact Lens Conversion Calculator
- Contact Lens Vertex Calculator and Distance Chart
- Toric Contact Lens Calculator
- Contact Lens Calculators: Conversion, Vertex, and Toric
Contact Lens Calculator Alternatives: OptiExpert, Simplifit, and Independent Tools names the brand portals. Convert spectacle prescription to contact lens parameters on this site, then fit and verify on eye.