Good news:
- They fit over my glasses and stay on my face by themselves.
- They add what I consider to be a completely unacceptable amount of CA.
- They cut sharpness and contrast.
- They have no adjustments for different size images or pair separation, other than moving closer or farther from the screen.
In my opinion, these things are a fundamentally bad idea, suffering further from shortcuts in manufacture. Much as I dislike red/cyan anaglyph glasses, I would much rather use those than these prism glasses.
To illustrate...
Here are the glasses themselves -- two thick plastic prisms mounted in a folding plastic frame.

Here is a setup to show what the glasses do.

This is looking through the glasses, with the camera placed another couple of feet back. At recommended 60 cm viewing distance, the glasses allow my eyes to look roughly straight forward and see a pair of images with about 8-9 inches between centers. (It looks like 7 inches in the picture shown here, but that's because of shooting with a single camera moved farther back. Through my eyes at 60 cm, it was 8-9 inches.)

Cropping closer on that same image, we can start to see the CA.

Then, to examine the image quality more closely, I set up at 60 cm away from my 22" monitor, used Excel to put a little black-and-white pattern on the screen, and shot the screen with a roughly 175 mm lens under 3 conditions.
1) Just the screen, nothing else in front of the lens. Pardon the moiré -- resampling pixels is always a bad idea.

2) The screen as seen through a Wheatstone type viewer that uses mirrors:

3) The screen as seen through the prism glasses:

I think you're probably convinced about the CA at this point, but since I have the images handy, here's a closer view:
1) Just the screen, nothing else in front of the lens.

2) The screen as seen through a Wheatstone type viewer that uses mirrors:

3) The screen as seen through the prism glasses:

I hope this is helpful.

--Rik