Again and again one hears of so-called near-death experiences. As the name suggests, this is constructed by the brain as long as it is not dead. So it is fantasies that the brain produces.
Near-death experiences are often reported and heard because it is believed to give an insight into the state of death and fear of death.
Of course, this is not the case: Either the brain is still working, then it is not dead (and can report such 'experiences', or else it is dead, then it is no longer working and cannot report
either).
So to conclude from an experience close to death what is happening in death is nonsense.
They are two completely different states. Life is not death; Death is not life.
On the part of neuroscience, near-death experiences are viewed as the result of temporary impairments of important brain functions.
Shortly after a cardiac arrest, the brain is no longer supplied with blood and oxygen, and the normal process is stopped. Perception is severely restricted and imagination fills the gaps.
In near-death life, of course, as in sleep and dreams, the functions of the forehead are switched off. There are no central processes.
Those affected experience hallucinatory experiences, mostly with light and tunnel experiences.
The tunnel vision can be traced back to damage to the visual cortex, the light from the tunnel to a narrowing of the visual field.