Integrity Freeform Lenses with

IOT Steady and Steady Plus Methodology

Patented Freeform Lens Technology by

IOT Logo & Tagline

Reducing Swim


The uncomfortable feeling of unsteadiness experienced when wearing and trying to adapt to progressive lenses is commonly known as the “swim effect” .

Mean power error or spherical equivalent power is the cause of the "swim effect" and can be a problem in peripheral lens optics.

Steady Methodology reduces mean power error almost to zero in the lateral areas of the progressive lens providing improved image stability. The wearer experiences immediate improvement in overall visual performance. 

Past efforts to reduce swim effect in progressive lenses have primarily focused on the reduction and precise placement of unwanted cylinder error in the lateral areas of the lens. However, unwanted mean power also plays a significant role in the perception of swim effect, and in overall wearer satisfaction. Steady Methodology changes that.

Distribution of spherical equivalent power error with
Steady Methodology and Steady Plus Methodology

camber blank RS
camber rx design computation RS
personalization parameters RS

Traditional Progressive Lens

A freeform lens computed without Steady Methodology

Lens with Steady Methodology

A freeform lens computed with Steady Methodology

Lens with Steady Plus Methodology

A freeform lens computed with Steady Plus Methodology - Available only on Camber blanks.

In a double-blind study, test wearers compared the same progressive design, one with Steady Methodogy and the other without it.





Steady Methodology Explainer Video

Integrity Freeform Lens Technologies


Steady Methodology

Non-Compensated Design


Basic is the entry-level technology to make digital lenses. Progressive lenses made with this technology will have the progressive surface on the back of the lens, and a simple curve, typically a sphere, on the front side. The progressive surface is calculated using IOT's Steady Methodology providing improved performance over conventional progressive lenses, with the accuracy and flexibility of the digital freeform process.


Steady and Digital Ray Path 2

Compensated Design


The most advanced technology to make digital lenses. Advanced-level technology uses both  IOT's Digital Ray-Path® 2 and Steady Methodology to take into account the real measured or default wearer position of the lens and the natural movements of the human eye. The result of this innovative calculation method is a progressive lens that is personalized and provides better vision in all zones of the lens.


Camber, Steady+, and DRP2

Compensated + Camber Blanks


Camber Technology combines the Advanced technology with the unique, continuously changing surface of the specially designed lens blank. When combined with a back surface design using IOT's Digital Ray-Path® 2 and IOT's Steady+ Methodology, both surfaces work together to accommodate an expanded power range, offer better cosmetics for many prescriptions, and yield user-preferred near vision performance.

* When comparing to other brand's "good better, best" options, it is important to note that the "Advanced" technology is equivalent to the "best" on the market, while Camber takes it to another level, incorporating the Advanced technology PLUS the special Camber lens blank, making it unlike any other lens available. What's more, you easily choose the ideal design for your customer or patient based on Rx or lifestyle and THEN select from "good, better, best" ensuring the most ideal and customized outcome for their visual needs.

Steady Methodology

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Ray-Path 2

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