<prompt> Enophthalmos is due to plasy of-Levator palpebrae superiorisSuperior tarsal muscleOrbitalis muscleTenons Capsule instability  <response>: Tenons capsule instability is a major cause of enophthalmos, as it forms all the major ligament of the orbit which suppo the globe in the orbit. Ref: Duanes Clinical ophthalmology, vol.2, chapter 48, p.5 