In addition to mathematically compensating for oblique aberrations, IOT Digital Ray-Path 2 adds the intelligent use of the wearer’s accommodation: the small power adjustments the eyes naturally make to view objects at different distances.

Pushing the limits of geometry in lens personalization

IOT Digital Ray-Path 2 pushes the limits of geometry in lens personalization by incorporating the wearer’s accommodative capacity in the final lens calculation to further minimize oblique aberrations.

Oblique aberrations, found in any lens, include astigmatic and spherical power errors. These errors create an out-of-focus image as the wearer’s gaze moves away from the optical center of the lens. Eliminating them completely is not mathematically possible. Some residual power error remains, causing a slight blur.

The potential of accommodation

The correlation between eye accommodation, the accommodative object space, and compensated power has been well-established for some time. However, lens calculation technology has, until now, lacked the sophistication required to produce free-form digital lenses that fully capitalize on this understanding.

Accommodation refers to the wearer’s innate capacity to adjust focus for varying distances without the need to shift their eyes or head, achieved by the contraction or relaxation of the eye’s lens. IOT Digital Ray-Path 2 integrates this aspect into every lens calculation it performs. Furthermore, IOT Digital Ray-Path 2 takes into account the accommodative object space, which encompasses the range of clear visual points for each direction of gaze.

IOT Digital Ray-Path 2 operates in harmony with the natural capabilities of the human eye. By harnessing the inherent abilities of the visual system, it enhances the optimization of personalized lenses.

The mathematical algorithms of IOT Digital Ray-Path 2 leverage the eye’s natural capacity to offset a portion of the spherical component of oblique aberration.

Moreover, IOT Digital Ray-Path 2 accounts for the subtle adjustments in power that wearers can instinctively make at each focal point. This approach effectively minimizes oblique aberrations, resulting in superior visual clarity for the wearer.

Here’s how it works

IOT Digital Ray-Path 2 calculates a unique back surface design for each lens with a three-step optimization process.

The eye lens system

First, it creates a simulation of the complete system that includes the eye and considers all available information on the wearer, frame, and lens blank.

Accommodative object space

Next, it incorporates the wearer’s natural ability to accommodate including the accommodative object space, the visual range associated with each direction of gaze.

Minimization of oblique aberrations

Finally, it analyzes and minimizes oblique aberrations at various distances and for each direction of gaze over the entire accommodative object space. The result: extremely clear vision and precise focus.

Lens personalization

  • Prescription & Addition
  • Monocular Pupillary Distance (MPD)
  • Wrap Angle (ZTILT)
  • Back Vertex Distance (BVD)
  • Pantoscopic angle (PANTO)
  • Pupil Height (HT)
  • Frame dimensions (VBOX/HBOX/DBL)
  • Near Working Distance


11% of gaze directions are now optimized* taking into account the wearer’s accommodation capacity.
43% of gaze directions are now optimized* taking into account the wearer’s accommodation capacity.
99.5% of gaze directions are now optimized* taking into account the wearer’s accommodation capacity.

Theoretical study carried out on a single vision lens.
[+3.00 +1.00 × 45°], 6 D base, index 1.5.

* Blur <0.18 D.


  • Wider fields of view.
    Reduced areas of blur result in wider fields of view for wearers.
  • Precise and comfortable vision.
    For all working distances and any direction of gaze making lenses with IOT Digital Ray-Path 2 technology ideal for everyday wear and for viewing electronic devices.
  • A more consistent wearer experience.
    Perceived power distributions remain stable, regardless of Rx or base curve. This is especially beneficial for patients with high prescriptions or large or wrapped frames.
  • Near elimination of peripheral blur.
  • Features


    The design is further enhanced, when desired, by a complete set of individualization parameters that take into consideration the unique attributes of the frame and the preferences of the wearer. If no parameters are provided, IOT Digital Ray-Path 2 will utilize default values.

    Compensated power

    Lens power differs from prescribed power. The design is calculated, point by point, to ensure wearers perceive the proper power when looking through their lenses at every distance and direction of gaze, including near distances for viewing electronic devices.

    Optimized for accommodative object space

    IOT Digital Ray-Path 2 incorporates the intelligent use of the wearer’s accommodation into the traditional calculations for reducing oblique aberrations, resulting in a superior personalized lens. Oblique aberrations are minimized more effectively than ever before.


    The perceived power distribution remains stable, regardless of the prescription or base curve. This is especially beneficial for high prescriptions and large or wrapped frames.