<prompt> Enophthalmos is an uncommon feature of Horners syndrome. Enophthalmos is due to palsy of:Levator palpebrae superiorisSuperior tarsal muscleOrbitalis muscleInferior tarsal muscle  <response>: Enophthalmos sinking of the eye is the inward displacement of the eyeball. It results from paralysis of the orbitalis muscle a smooth muscle that spans the inferior orbital fissure and may contribute to maintaining the normal position of the eyeball. Ref: Grays Basic Anatomy By Richard Drake, A. Wayne Vogl, Adam W. M. Mitchell, 2012, Page 467. 