But resolution is limited.
If you are so sure it's "obvious" you can extract recognisable faces from reflections on photographs containing eyes - show me you can do it using any photo containing a headshot you can find on Google Images or Flickr... Or even any staged photo you have or can take - showing enough resolution from a headshot that you can extract recognisable faces from eye reflections. I have a 12 megapixel camera in my phone - and I'm not convinced I could reliably take a photo of someone's face with enough resolution to pick to recognisable detail in a reflected face in an eyeball...
I am sorry, but megapixels do not a good camera make.
My Fuji X100 (35mm prime) and Nikon D200 (50mm prime), the latter from over a decade ago, both easily produce clear pictures in eye reflections when the light is good.
That said -- have you actually tried?
I just took a selfie with my MotoG5s front camera, and I can see a face from my FB feed reflected in my eye. And that's in crappy office lighting, from a screen with brightness turned down to minimize strain!
>Or even any staged photo you have or can take
To re-iterate: it is ridiculously easy to take such a photo with a real camera with decent lens. Modern cell phone cameras are capable as well if the light is good.
Here's a non-attempt: just a crop from the selfie I took
You can't, because the information isn't there. The same way you can't read a book that is closed, even with a super computer.
"Moon landing? Bleh, who cares. We know the moon is a planetoid and how far it is, why is it interesting when we land on it? I've never met anyone that didn't know it was possible to land on the moon."
The contents of the paper is pretty much contained in its title. They took photos and saw faces reflected in eyeballs! That's it!
People have been doing that since, well, cameras were invented. And people have been staring into reflections in eyes since forever.
"My face in thine eye, thine in mine appears,
And true plain hearts do in the faces rest;
Where can we find two better hemispheres,
Without sharp north, without declining west?"
-John Donne (1572-1631)
I've never met someone who doesn't know that eyes are reflective.
>"Well now it's not."
It never was. Being able to turn corners in a picture was the science fiction part, not the fact that those corners had people in them.
Jesus how am I the only person here who understands this concept. It really isn't rocket science... the solution is solved by technology, not by progressive "methods" of using that technology.