How much magnification required to see stylus?

How much magnification is required to clearly to be able to judge the condition of a stylus?
Many posts from folks who 'know' mention even with the ability to see the stylus tip, it is VERY difficult for a non-expert to see if the tip is worn.
Even Shure with that dealer stereomicroscope the wear was 'inferred' from particular ways the light refleted off he tip rather than direct 'SEEING' the wear.
So it is basically damn near impossible to 'see' the wear on a srylus in any meaningfull way.
As the posts mention, the best way to tell is a stylus is getting worn is hearable 'inner groove distortion' getting worse.
When it is starting.. the stylus is still not damaging the Lps..
So THAT is the best method to detect wear. So it seems.
You can Google the idea and read all the stuff for yourself.
I googled Shure stylus microscope. and Stylus wear
IMHO, 15X magnification is the minimum, higher will be better.
Elizabeth is correct. To judge wear, you need at least 200X and up to 500X is helpful for micro types. You also need high intensity lamps on either side of the stylus. Then you have to know what you're looking for and how to judge.

The professional Audio Technica scope was 100, 300, 500X.
The later Shure scope was 200X.
I think a scanning Electron Micograph might tell you if it were worn. The problem is that using the stylus for the EM pictures destroys the stylus. If you could get certain wear states to correspond to a typical sound like Elizabeths inner groove distortion a series of worn scanning electron micographs vs nomal unworn styli would be useful.
Attached is a link to a YouTube video showing examples and explaining cartridge wear.

The reason for the question is that I was thinking of buying an USB microscope, they go for around 50$ on amazon. I was wondering if these would be sufficient for this purpose. 800x should do it.

Has somebody tried this.
You can get inner groove distortion from a dirty stylus. You can check for gunk buildup on a stylus with an 8x loupe. I do and it works.

Then I clean the stylus with a Magic Eraser, brush away the residue, use the loupe to ensure that the stylus is clean and play the cartridge again. If the distortion goes away it was a dirty stylus. If the distortion remains and your alignment is good, it's probably time for another stylus.