Comparison

Multifocal Lens Analyzer vs CAS_Calc

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Multifocal Lens Analyzer

This application assists vision science professionals in measuring visual acuity defocus curves for multifocal lenses. It offers basic features for free and advanced functionalities through a pro subscription, enhancing clinical practice and research.

Highlights
  • Visual Acuity Defocus Curves
  • Defocus Lens Range Selection
  • Snellen Optotypes
  • Contrast Sensitivity Defocus Curve
  • Historical Database Storage
  • Data Export to .CSV
Features
Read full description

THIS IS A PROFESSIONAL APP BASED ON EVIDENCE JUST FOR PROFESSIONALS IN VISION SCIENCES The most popular method in clinical practice for evaluating the visual performance through the field with a Multifocal Intraocular Lens or a Multifocal Contact Lens is the Visual Acuity Defocus Curve. This application allows you to measure Defocus Curves with several advantages versus conventional charts. The application is based on a Freemium model, just downloading the App you will have access to the following options: 1.- Visual Acuity Defocus Curves 2.- Two possible distances (2 m and 4 m), 3.- Selecting a range of possible Defocus Lenses from +5.00 D to -5.00 D 4.- Snellen optotypes. BEFORE DOWNLOADING ON IPHONE YOU SHOULD KNOW: The functionalities differ depending on the installation on an iPad or iPhone: 1.- You need an iPad for conducting the Defocus Curve measurement 2.- If you install the MLA in an iPhone this only serves as a remote control, you will still need an iPad to measure the Defocus Curve 3.- You can access to more information about the procedure at:  https://defocuscurve.com/en/testing-defocus-curve A PRO version is also included with several options such as: 5.- Contrast Sensitivity Defocus Curve 6.- Optional steps of +/- 0.25D around de 0D step 7.- Sloan Optotypes (ETDRS) 8.- Auto-calculation of Sphere with Rx, Defocus and Distance 9.- Remote Control with another IOS device 10.- Historical Database to Store Defocus Curves 11.- Assign Defocus Curves to several Protocols (MIOLs or MCLs) 12.- Store Additional information (pupil, Rx, month, etc) 13.- Export Data to .CSV 14.- Calibrated considering several iPad models or the possibility of a personalized calibration. 15.- Area under the defocus curve calculation. INFORMATION ABOUT PRO SUBSCRIPTION The Multifocal Lens Analyzer is a freemium app. If you want to access to all the services you have to buy a PRO auto-subscription for 49.99€ (prices can vary between countries) for a period of 1 year. The payment will be charged to your iTunes Account at confirmation of purchase. Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal. Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase. Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable. You can find our terms and privacy policy at https://www.defocuscurve.com/en/2-documentation/25-terms-conditions SUPPORT AND QUESTIONS You can access our webpage www.defocuscurve.com to view all the research validation papers or the authors that have used the App in their research. You can also join our community in order to ask any question or to receive support: www.facebook.com/groups/qvisionacademy/

About

CAS_Calc

Features
Read full description

CAS IOL Calc calculates the power of an intraocular lens. It is written for ophthalmic surgeons performing cataract surgery, and for anyone working with ocular biometry. FOUR ENGINES, SIDE BY SIDE • CAS Rx — the engine for routine work. Gaussian optics with a thick corneal model; the machine-learned part is the effective lens position and nothing else. Toric, suitable for all eyes. • CAS classic — the original Castrop formula with the C/H/R constant triplet. It calculates what the web version at iolcon.org calculates. • CAS AI — pure machine learning without any optical calculation, a feasibility study and a cross-check. Spherical only, with hard limits. • SRK/T — the 1990 formula, included as a yardstick because the comparison has been asked for repeatedly. We do not recommend it for clinical use. Where the four diverge, that divergence is information in itself. TWO MODES • Simple — one eye, the short form, the result directly below it. The corneal refinements sit behind a switch. • Full — both eyes in turn, with side comparison, a note field, QR import and a printable calculation sheet: one A4 page, both eyes side by side, with the inputs, the constant footing, the power table, the axis sketch, every note and the scope and limitations of the engine. FOUR MODULES The menu "Module" under the title switches between four calculation paths; the case in the main calculation stays as it is. • IOL calculation — the routine case, the lens in the capsular bag. • Add-on IOL — the supplementary lens in front of a lens already implanted, from the refraction and the pseudophakic anterior chamber depth. • IOL exchange — the replacement lens for a pseudophakic eye; the cylinder comes from the refraction, the radii run alongside as a cross-check. • Secondary implantation — the eye without capsular support, with the lens position set by hand. Each module has its own inputs, its own note field and its own printable sheet. WHAT THE APP DOES • Toric calculation with axis rose, misalignment and residual refraction • Result table with spherical equivalent and the whole lens (sph/cyl) • Refined cornea: posterior surface, thickness, tomographic cylinder • Corneal spherical aberration, derived from the radii and the asphericity (Q or e) and calibrated to the CASIA2 • Post-refractive corneas via funny cornea and the posterior radius • Read biometry from the QR code on the device printout, through the camera or from an image or PDF; the code format is documented at https://iolcon.org/download/LPCM_QR-Import.pdf • Warnings instead of silent extrapolation: percentile limits on every field, eye rarity score, side comparison of the pair, a note when keratometric and tomographic cylinder diverge • Lens catalogue with optimised constants; unknown lenses via the A constant • Full manual inside the app, in three languages • German, English, Italian PRIVACY Everything is calculated on the device. No account, no sign-in, no network connection, no data collection. There are no fields for a name or a date of birth. The report carries no patient identifier. The only things kept on the device are settings and lenses you create yourself (name and constants) – never measurements. IMPORTANT CAS IOL Calc is not a medical device. It is for investigational use. Every clinical decision remains with the treating physician. The models were trained on IOLMaster 700 measurements; for other biometers a slight loss of accuracy cannot be excluded. The limitations of each engine are shown permanently in the result panel, on the printout and in detail in the manual. The basis is the Castrop formula: Langenbucher A, Szentmáry N, Cayless A, Weisensee J, Wendelstein J, Hoffmann P. Considerations on the Castrop formula for calculation of intraocular lens power. PLoS One 2021;16(6):e0252102.

Screenshots

Multifocal Lens Analyzer2 screens
CAS_Calc4 screens

Verdict

The call

The clearest difference is in-app purchases: CAS_Calc at none against Multifocal Lens Analyzer's 1. CAS_Calc also leads on update cadence (fortnightly vs every 2 months). Multifocal Lens Analyzer's advantage is iOS requirement (15.6 vs 17.0). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Multifocal Lens Analyzer sells 1 in-app purchase, starting at $45.99 per year. CAS_Calc asks for nothing beyond the download.

UpkeepUpdate frequency

Multifocal Lens Analyzer ships an update every 2 months, CAS_Calc fortnightly. The most recent releases landed on October 25, 2026 and October 17, 2026 respectively.

Scorecard3 real differences · 6 level
Multifocal Lens Analyzer versus CAS_Calc: the parameters behind the verdict, then further details
ParameterMultifocal Lens AnalyzerCAS_Calc
PriceFreeFree
Rating3.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyEvery 2 monthsFortnightly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.6 — better17.0
Further details — not scored
Size5 MB16 MB
Age rating4+4+
DeveloperQvision, Departamento de OftalmologíaPeter Hoffmann

In-app purchases

1 purchases

Multifocal Lens Analyzer

Subscriptions1
  • Pro$45.991 Year
None

CAS_Calc

No in-app purchases

Questions

Is Multifocal Lens Analyzer free?
Multifocal Lens Analyzer is free to download, with in-app purchases available.
Is CAS_Calc free?
CAS_Calc is free to download, with no in-app purchases.
Do Multifocal Lens Analyzer or CAS_Calc have ads?
Neither Multifocal Lens Analyzer nor CAS_Calc shows ads.
Which is updated more often, Multifocal Lens Analyzer or CAS_Calc?
Multifocal Lens Analyzer ships an update every 2 months, and CAS_Calc fortnightly. Most recently, Multifocal Lens Analyzer was updated on October 25, 2026 and CAS_Calc on October 17, 2026.

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