I did a little reading about Hemianopsia and came up with a very simple test about 15 years ago. It was a simple winforms app. One could write it/vibe code it very quickly in just about anything.
The test was run seated at a desk with a 24'' monitor. I drew a small square in the center of the screen on a back background and created a regular grid of dots which could be subdivided. Each small dot at random was briefly shown and I recorded the time it took him to hit a key. The defaults were .5 to .8 seconds and an off time from .75 to 2.5 seconds on a 7x5 grid with subdivisions for the areas he had trouble, but it's long enough ago that I don't remember what settings he preferred. The sample file I have to hand has 140 dots.
I set it up so that he could customise the number of columns and rows and the number of subdivisions to target his vision loss without having to spend too much time where it didn't matter. The outputs were a grayscale image of the reaction times and the reaction time values. It was helpful to preview all the dots before starting the test.
The main issue with the test was to keep it relatively short. If it took too long he found it boring and caused a bit of eye strain.
If I were to write it again I would to move the center square occasionally throughout the test, and then offset the test grid from that location. Unfortunately he didn't have much time and it eventually became a bit stressful to know the rate of progression of his disease so he/we let it go and I never tried to ease the eye strain issue.
> "walk to the right" on sidewalks and such, I prefer to stay as left as I can on a path."
Visit Australia for a mostly keep left experience (at least in the past) :)