Physical forces involved in pseudophacodonesis and iridodonesis.

Studies of high-speed motion pictures of the eyes of patients after extracapsular (EC) and intracapsular (IC) cataract extraction show that pseudophacodonesis and iridodonesis are the result of oscillations of the fluids in the anterior segment of the eye. These oscillations, initiated by movement of the eye, result in shearing forces on the corneal endothelium which may result in damage. Similar motion of the vitreous causes shearing forces which may damage the retina.