2020 continues. Is there proof of heaven? once again, Elizabeth Vargas.

8 million Americans claim to have had a near-death experience, but neurosurgeon Eben Alexander never thought in a thousand years honey would be one of them.

- What'd you think those were?
- Fancies, hallucinations.

He was a man of science he didn't believe in it. That is, he says, until it happened to him.

- Let's talk about how you got sick. You woke up in the middle of the night feeling ill and in pain.

It was like being struck by a freight train. 4:30 in the morning, woke up, I never had anything like that before. My last words to my wife, “don't call 911. Trust me, I'm a doctor, I just a muscle spasm”, and and I was gone.

Doctor alexander had a rare and deadly form a bacterial meningitis which was infecting his brain. In a matter of hours this healthy man was on death's door. By the time they got him to the hospital he was in a coma.

- So your wife was being told that you might die?
- And that she would be raising our two boys without me.

But as his body lay in their hospital bed with no recognizable brain activity, Doctor Alexander says he had already begun an astounding journey, a journey to a place he’d said didn't exist.

- Did you believe in heaven?
- When I was younger, I thought a heaven and a loving God made sense, but through my academic neurosurgery career, uhm... I saw less and less that that could be the case.

The journey began, he says, in a dark formless place without memory, language or time, but then...

- I was rescued from that by the spinning melody of light that came closer and opened up and was a rip in the fabric of reality that just opened up around me.

- You describe this world as hyper-vivid.
- The colours were extremely vivid, with millions of butterflies, and these flowers blooming blossoms opening as we flew by.

... and by his side an unknown presence.

- There was a person guiding you, a beautiful girl, as you described her. Tell me what she look like.
-  she had a beautiful face with a wide smile and high cheekbones and absolutely gorgeous
clear blue on yes. She never said a word to me. And she would look at me and the thoughts would come directly into my... into my mind, into my awareness.
- What thoughts?
- And the thoughts were: you are loved, you are cherished, there's nothing you can do wrong. I always remember being told: we will teach in many things but you’ll be going back.

... back to the hospital where his wife kept her vigil and his doctors were giving up hope. On the seventh day his coma...he opened his eyes.

- It was just nothing but a miracle.

His first words, the very words he'd heard from his guide, that blue eyed girl.

- All is well, don't worry, all is well.

Within weeks, Ebin Alexander had made an astonishing full recovery.

- How are you different after going through this experience?
- My family says I'm nicer...
- Ha ha, that’s a good thing.
- I would say... Really, it’s changed me in every way by realizing that our souls are
eternal.

The book he has written, “Proof of heaven”, has sparked a lot of controversy

- You know you do have sceptics out there who are just saying, it’s not uncommon for people near death to have all sorts of funky things going on inside their bodies.
- Well that's why the fact that I had meningitis, that was so severe, mean that should not have allowed for any experience.

++++++ his brain was so completely shut down that the visions he had could simply not have been generated there. He said he wrote down everything he remembered, now in his book, before speaking to anyone, so as not taint his memory.

- You then went on to read about other people's near-death experiences. Was it striking how similar what you had written was to what they had experienced?

- It was absolutely astonishing!
- I really felt the white light was God.
- I stepped back and I saw my grandma.
- You could see peace, you could see love.

- In all the other after life stories, everybody told of being guided by a loved one who had died. You had as your guide a girl you'd never met.
- I must say that was very haunting. Why would I go through all that and not have my father there? My father, who was a neurosurgeon. I idolized him, and he’d passed over four years earlier. Why wasn't he there?

And wide the blue eyed girl instead? Doctor Alexander had been adopted as a child. Years later he found his birth family. All except for one: his birth sister, who died before he met her.
- Her name was Betsy.
- How old was she when she died?
- She was a 36-years-old.
- So Betsy you’d never met.
- I just heard what a beautiful, loving soul she was. How she, how she worked in a, in a rape-crisis centre and took care of many people who are unfortunate and... she was just a very loving, loving person.
- How was it that you came to see a picture of her?
- My birth sister Kathy had promised to send me a picture of Betsy. And it was about four months after my coming out the hospital, and that picture arrived.

He opened the envelope and saw her for the first time. The photo, he says, was of that blue-eyed girl from his vision.

- And it was so stunning. In that picture was almost as if she’s saying, “Do you get it now?”, and
I cannot tell you how powerful that was. There was no mistaking it, that's exactly who it was.

Life is back to normal at the Alexander household these days. There are soccer games to watch, dinners to be shared, grace to be said. But Doctor Alexander says he's on a mission now.

- I hope to tell my story to everyone I possibly can around this world because I think it will help this world to be a much better place.