prop·to·sis 
(prŏp-tōsĭs)
(prŏp-tōsĭs)n. pl. prop·to·ses (-sēz)
Forward displacement of an organ, especially an eyeball.
[Late Latin proptōsis, prolapse, from Greek, from propiptein, to fall forward : pro-, forward; see PRO-2 + piptein, ptō-, to fall; see pet- in the Appendix of Indo-European roots.]