Finally, one of the most famous aspects of near-death hallucinations is moving through a tunnel toward a bright light. Although the specific causes of this part of near-death experiences remain unclear, tunnel vision can occur when blood and oxygen flow is depleted to the eye, as can happen with the extreme fear and oxygen loss that are both common to dying.
Altogether, scientific evidence suggests that all features of the near-death experience have some basis in normal brain function gone awry. Moreover, the very knowledge of the lore regarding near-death episodes might play a crucial role in experiencing them—a self-fulfilling prophecy. Such findings "provide scientific evidence for something that has always been in the realm of paranormality," Mobbs says. "I personally believe that understanding the process of dying can help us come to terms with this inevitable part of life."
One potential obstacle to further research on near-death experiences will be analyzing them experimentally, says cognitive neuroscientist Olaf Blanke at the Swiss Federal Institute of Technology in Lausanne in Switzerland, who has investigated out-of-body experiences. Still, "our work has shown that this can be done for out-of-body experiences, so why not for near-death-experience-associated sensations?"