There are many options to view stereoscopic image pairs.
There are two unassisted methods to view image pairs.
Parallel viewing. The images are placed the way they would be with a viewer. The right image is in front of the right eye. Since it's very difficult to separate convergence from focus, I've successfully used this method once. This works only with ...
One of the simplest methods of emulating stereo viewing also requires no special software to view or create: animated GIF. Most full-featured image editors can create animated GIF files from a set of images; some will automate the process more, but it's simple enough to do manually without undue effort.
This works both with conventional stereo pairs and ...
The method I use to view stereoscopic images - where two prints are side by side, is by:
placing the image a foot or two away then.
place my hand vertically as a divider - thumb in front of my nose, all fingers up, between my eyes
looking at the picture - move closer / further (depends on dimensions) to permit each image to overlap... when they overlap it's ...
There is a possible low-tech solution which I saw used in Edinburgh's Camera Obscura.
Simply print out the images side be side (no gap between them, identical sizes) and put a (mountain) fold down the middle. Put your nose against the fold. Voila! Each eye sees a different image. No crossing eyes or headaches involved.
In the display in the camera obscura, ...
There is software that creates a similar effect:- virtual reality.
A stereoscope will present each eye with a different image to give the illusion of 3D. This is exactly what VR does.
However, you would need to scan your images and show them to each eye in a VR headset.
Unless you can get them into an old Nintendo 3DS, which simulated 3D on a 2D platform.