Occlusion
Occlusion is the optical blocking of something by something else.
In a near-eye display, an occlusion layer can be done using soft-edge occlusion or hard-edge occlusion. Soft-edge occlusion is blurry in concept, and is done in the Magic Leap 2. It simulates the effect of having an object close to the eye occluding part of the vision, but the eye is focused past it.
Hard-edge occlusion is a method to do occlusion near to the eye such that an occluded edge appears to be sharp, rather than blurry.