Cranial window implant

Researchers at University of California, Riverside have developed a transparent prosthetic implant that can replace a piece of skull and provide a window to the brain that can be used repeatedly to monitor a site of an injury and deliver treatment over an extended period of time without additional craniectomies.
http://www.medgadget.com/2013/09/transparent-cranial-window-implant-for-brain-monitoring-laser-therapy.html