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by interloxia 292 days ago
Do you also track /check your field of view?

A long time ago I made a simple tool to check my father's visual field changes due to cancer. At first he found it interesting to track his condition. Unfortunately it accurately tracked his condition and he, in my option wisely, stoped using it.

All the best managing and tracking

1 comments

I never have really tried to measure my own peripheral visual field - no! I am not sure how I would track it - how did you?

I mostly notice bumping into things on my left side. While generally people "walk to the right" on sidewalks and such, I prefer to stay as left as I can on a path. For example, walking home through downtown, I like to try to keep my left shoulder as close to buildings as I can, to avoid people coming up behind me on my left side, since I always risk bumping into them. I always choose seating in venues that is very left of center as well.

While I generally do not have serious seizures resulting in falls, it's funny that the fall detection on my Apple Watch has only ever gone off when I accidentally bang my left wrist against a door frame because of my poor peripheral vision.

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) :)

This sounds like such a cool useful project!

I had to look up the proper name for it, but I have always had my visual field medically tested with a "Humphrey" visual field test machine in a hospital:

https://www.ncbi.nlm.nih.gov/books/NBK585112/

TIL, there is also something called the "Goldmann" perimeter test.

Visiting Ireland, as a kid, was fun for sure! I remember my father driving a "right-hand drive" car that had the steering wheel on the opposite side of what I was used to - on the opposite side of the road from what I was used to - all, while shifting the manual transmission with his left hand, but the floor pedal arrangement was the same.

Curiously, both of my parents are left-handed, but I am right-handed. I have no family history of epilepsy either! Maybe I am adopted.