A model of the mechanics of binocular alignment

Design of a Humanoid Robot Eye

“…The human eye has an almost spherical shape and is hosted within a cavity called orbit; it has an average diameter ranging between 23 mm and 23.6 mm, and weighs between 7 g and 9 g. The eye is actuated by a set of six extra-ocular muscles which allow the eye to rotate about its centre with negligible translations (Miller & Robinson, 1984;Robinson, 1991). The rotation range of the eye can be approximated by a cone, formed by the admissible directions of fixation, with an average width of about 76 deg (Miller & Robinson, 1984).…”

“…The rotation range of the eye can be approximated by a cone, formed by the admissible directions of fixation, with an average width of about 76 deg (Miller & Robinson, 1984). The action of the extra-ocular muscles is capable of producing accelerations up to 20.000 deg sec -2 allowing to reach angular velocities up to 800 deg sec -1 (Sparks, 2002).…”

“…The four recti muscles have a common origin in the bottom of the orbit (annulus of Zinn); they diverge and run along the eye-ball up to their insertion points on the sclera (the eye-ball surface). The insertion points form an angle of about 55 deg with respect to the optical axis and are placed symmetrically (Miller & Robinson, 1984;Koene & Erkelens, 2004). (Fig.…”

“…Saccades have duration of the order of a few hundred milliseconds, and their high speed implies that these movements are open loop with respect to visual feedback (Becker, 1991); therefore, the control of the rotation of the eye during a saccade must depend only on the mechanical and actuation characteristics of the eye-plant. Furthermore, the lack of any stretch or proprioceptive receptor in extra-ocular muscles (Robinson, 1991), and the unclear role of other sensory feedback originated within the orbit (Miller & Robinson, 1984), suggest that the implementation of Listing's Law should have a strong mechanical basis. Although saccades are apparently controlled in open-loop, experimental tests show that they correspond to regular eye orientations.…”

Simulation of Active Eye Motion Using Finite Element Modelling

“…Descartes pioneering work for eye modelling in 1630 see Descartes 1972 has been continued by Listing, Ruete, Donder, Helmholtz and many others until now details can be found in works by Simonsz & Spekreijse 1990, Donders 1864and Fetter et al 1997. Simonsz & Spekreijse 1996, Clement 1982and Miller & Robinson 1984 suggested some computerized model for studying eye behaviour. Recently Ghosh et al 2009 employed quaternions and Bayro-Corrochano 2003 used geometric algebra for eye modelling with lumped parameters.…”