Forum Discussion

hoppingbunny123's avatar
hoppingbunny123
Rising Star
14 days ago

I saw a optical illusion I share here

My phone was off and the phone glass was reflecting the computer lcd monitor image.

 

I had a magnifying glass on the desk, both sides of the magnifying glass are curved.

 

I held the magnifying glass in my hand and enlarged the image the phone was reflecting.

 

What I realized was the eyes ipd sees the image in the phone differently, one eye sees more and less than the other eye.

 

And using a magnifying glass exaggerated this so what the eyes see is more and less of what the other eye sees.

 

But the mind makes both eyes see one image. The mind takes both eyes different images and makes them one image.

 

I imaging if two lcd screens shows the same image and positions the magnifying glass on each eye just so the eye will make two different images the same image. A stereogram.

 

 

2 Replies

  • steve_40's avatar
    steve_40
    Visionary
    13 days ago

    Congratulations, you've just reinvented… vision.

    Next week on Off Topic: I stare at a spoon and discover depth perception.

    After that, I'll hold a flashlight up to a mirror and publish my groundbreaking research on why light goes 'boing.'

    But seriously—yes, two screens + lenses = VR. You have successfully replicated the Meta Quest using a phone, a magnifying glass, and the raw power of curiosity. Somewhere an engineer just felt a disturbance in the force.

  • Slayemin's avatar
    Slayemin
    Meta Employee
    10 days ago

    Yeah, what you're describing is pretty foundational to what makes VR work. In meat space, our eyes see depth by measuring the small differences in what each eye sees, and our brain merges those two images to create "stereo depth perception" based on the distance between your eyes (aka, inter pupilary distance, or IPD).

    People are all different, so there's some subtle changes from person to person where their IPD varies by a few millimeters. Knowing a persons exact IPD is actually super important for correct rendering in VR -- we have to render slightly different images on each of the left and right displays to create the illusion of depth, so if someones IPD is miscalibrated, then the way they perceive the depth of virtual objects in VR can be off by quite a bit depending on the distance of the virtual object in VR space. You'll notice this if you are trying to touch the object and it appears either 1-2cm farther or closer than you think it should be -- that means your IPD calibration is slightly off and you're going to get horizontal binocular disparity errors (HBDE).

    What's interesting to me is that some people have lived their whole lives seeing the world without depth, not realizing they're not seeing depth, and then they put on VR goggles or 3D glasses and see in stereo for the first time, and then something weird happens in their brain which causes the optical neurons to rewire and correct themselves, and now they start seeing in stereo in real life... whoa