Wouldn't the easiest way to test it would be to blind your own character?
Normally, that's true, except you have too high an initial Wisdom to see if it made an impact (you have a initial 4x spell multiplier for Black Magic) and the spell itself is a 100% hit rate spell. I think the Basilisk's Stone Gaze spell (partial/gradual petrification) is unimpacted, so I believe this is the case.
I looked over the Spell subroutine code again, and while I'm not positive, it looks like Blind should have an effect. The reason it wouldn't on Remedy is because it's hard-coded to 10%. Check and see if it has an effect on normal damaging or healing spells. The code is a little convoluted, so I could be wrong. Let me know what you find.
Spell like that should work only half the time (though it gets the hit rate boost being solo) since the monster itself has no magic power to speak of (meaning he has a 1x spell multplier).. but it works all the time. So it must be ignoring Blind status as far as I can tell. I think that also applied to the Mist Dragon's damaging ColdMist attack.. where the damage wasn't reduced while Blind was inflicted.

The Mist Dragon has way too high a hit rate if part of the magic stat is added to the spell hit rate...