Incomplete rupture of the zonule with the displaced lens remaining behind the pupil. In dislocation, or complete rupture, the lens is displaced forward into the anterior chamber or backward into the vitreous body. When congenital, this condition is known as ECTOPIA LENTIS.

"Dislocation is a traumatic injury wherein the normal articulation between two bones at a joint is disrupted, resulting in the complete separation of the bone ends and associated soft tissues from their usual position."

The joint involving the CERVICAL ATLAS and axis bones.