on this topic for many decades.

There are a few cases reported of a born-blind patient who had died on the operating table.
While the medical personnel were making efforts at resuscitation, the non-physical part of
the patient had floated out of his/her body and was watching and listening to all the goings
on. The resuscitations were successful.

Post-op the patients, of course, were still blind. But they reported to the nurses and
surgeons what each one of them had been doing and saying during the resuscitation.
These medical personnel were astounded, but could give no "natural" explanation. How
could these patients have seen when they had never seen? They were born blind, and
still were blind.

To really go deeply into this subject, you'll have to do a lot (and I mean a LOT) of research.
There are many institutions of world-renown involved in the links given below: Just begin with:

www.IANDS.ORG
www.NDERF.COM
www.near-death.com