Homework Helper vs ToricTrouble

Make math easier with our app. Simply scan a problem or type it in to get fast, clear solutions. Perfect for students, homework help, and everyday calculations. Main Features (Subscription Required): • Scan math problems using your camera • Step-by-step solutions and explanations • Supports algebra, arithmetic, equations, and more • Fast and accurate problem recognition • Clean and easy-to-use interface Why You’ll Love It: • Understand how problems are solved • Save time on homework and studying • Great for students of all levels • Learn math in a simple, visual way Subscription Details: • Weekly access: $6.99/week with a 3-day free trial • Yearly access: $39.99/year 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. Your account will be charged for renewal within 24 hours before the period ends. You can manage or cancel your subscription anytime in your iTunes Account settings. Any unused portion of a free trial will be forfeited when a subscription is purchased. Privacy Policy: https://docs.google.com/document/d/1S5evwT2WvesoJpoOJYJx0nkS4NV7y6CaQ4pqkSqiCbE/edit?usp=sharing Terms of Use: https://docs.google.com/document/d/1bYnLbWEm7iN-M660On8jK8kuvKuPN9Rxnmgp9EIlj1o/edit?usp=sharing

Toric Trouble works up the outcome after a toric intraocular lens. The app calculates backwards: from biometry, implanted lens and subjective refraction it determines which of the three does not fit the other two. FOUR POSITIONS • Lens — which lens is actually at work? The main clinical question. • Refraction — what refraction was to be expected? Turning the axis simulates a misaligned lens. • Cornea — which cornea fits lens and refraction? Comparing it with the keratometry is the diagnosis. • Plausibility — all three checked against each other, naming the ghost astigmatism: what none of the three explains. FURTHER FEATURES • A recommendation where to rotate, what residual cylinder would remain at best — and whether an exchange is the better choice • Axis diagrams with uncertainty wedges from the actual measurement tolerances: cornea 0.30 D vectorial, refraction 0.25 D, read-off axis ±3° • Keratometric index selectable in four steps: 1.3375 (Javal), 1.332 (Zeiss), 1.3295 (Kooijman), 1.3281 (Liou & Brennan) • Effective lens position from the postoperatively measured anterior chamber depth instead of a prediction — this removes the largest uncertainty from the calculation • Surgically induced astigmatism (SIA) from pre- and postoperative keratometry • Plausibility check on every entry: impossible values block the calculation rather than yielding a result that looks like any other • Complete manual inside the app, in three languages CALCULATION CORE The basis is the Castrop formula, developed with Prof. Achim Langenbucher, Saarland University, and published peer-reviewed: Langenbucher A et al. Considerations on the Castrop formula for calculation of intraocular lens power. PLoS One 2021;16(6):e0252102 Langenbucher A et al. The Castrop formula for calculation of toric intraocular lenses. Graefes Arch Clin Exp Ophthalmol 2021;259(11):3321–3331 Both papers are linked inside the app, directly below the result. Where the app goes beyond what is published, it says so and describes the calculation path in full in the bundled manual. All calculation runs on the device, in C99 compiled into the binary. No account, no sign-in, no network, no advertising, no data collection. German, English and Italian. For ophthalmologists and other eye care professionals. Not a medical device; responsibility for every clinical decision remains with the user.