As an iai/kendoka, I can offer a little info. Before I rebooted on my training this summer, I was somewhat haphazardly training off/on during 05-06 (hardly a 2-3 hours a month, yeah, very little). There were a few regular (And still are) "center/target" zone practices you can do to improve such. Around spring 06, my left eye was injured and I was forced to wear a patch for a few weeks. To boil it down, I tried one simple "zone" practice and was -completely- off my mark. To be blunt though, even when I practice seriously now, I seldom do more than 7-10 hours (2-4 official) of "practice" a week. A fictional (or even hell, a real samurai) character like Guts trained/faced battle 24/7, means to an end/way of life. It should become second nature and eyesight should not be a liability (not trying to say Zatoichi isn't Bullshit...)
Wrapping things up, no, losing an eye to something one is comfortable and using on a daily basis that doesn't completely require eyesight isn't a big hinder.
Again, if you lost your eye today, you'd still probably be able to use a keyboard+play video games without going batshit that you couldn't make out where things were.
Wrapping things up, no, losing an eye to something one is comfortable and using on a daily basis that doesn't completely require eyesight isn't a big hinder.
Again, if you lost your eye today, you'd still probably be able to use a keyboard+play video games without going batshit that you couldn't make out where things were.