Model Types

The SEE++ system includes different mathematical models of research history and provides interactive comparability of simulation results among different model-based calculations. SEE++ implements four different models, from which two models simulate purely geometric characteristics of the oculomotor system.

model types

The fact that the purely geometric models do not contain force simulation and simulation of statics leads to the restriction that a “virtual” binocular test of eye motility, like the Hess-Lancaster test, cannot be performed. Nevertheless, string and tape models offer ideal introduction to a better understanding of the oculomotor system and its underlying geometric characteristics.

String Model and Tape Model are both “historic” modeling approaches, where the String Model assumes a muscle to always take the shortest path from its anatomical origin to its insertion on the globe, which allows a muscle to flip its muscle path from one side of the globe to the other when the eye rotates. The Tape Model prevents this large scale muscle side-slips by introducing a very simple simulation of intermuscular membranes. String and Tape Models both do not include the simulation of muscle “pulleys”.

The SEE-KID Model simulates “static” (non-moving) eye muscle “pulleys”, functionally described by Miller, Demer et al. The SEE-KID Active Pulley Model contains a simulation of the most recent physiological findings of actively moving muscle pulleys by Demer et al. which he called “Active Pulley Hypotheses”.

The SEE++ system also includes an implementation of the Orbit™ model which was developed by Miller and can be obtained from Eidactics ( However, according to the opinion of Joel Miller, neither this model implementation, nor all other model implementations contained in the SEE++ system are “correctly implemented”. For further information, please refer to Miller’s critique ( as well as to our response to Miller’s critique on SEE++ and our detailed analysis of Orbit™ 1.8.