In order to determine the mechanical properties of the vitreous which are characteristic for the extraction of foreign bodies, an oscillatory method was devised. The mechanical properties are described by a spring constant – relevant for the rubber elastic behaviour – and a friction constant characterizing the dissipative interaction inside the vitreous. The appropriateness of the data is demonstrated by the capability to predict the distance-time behaviour in strong, pulsed magnetic fields of ferromagnetic foreign bodies implanted into the vitreous of pig eyes.