If I'm honest I don't see why Dark Sight would be important. You don't get hit, but who cares? As long as you know where the more ideal gemstones/herbs are then there's no point going to the harder hitting areas. Even looking for Heartstones or those golden giant herbs. Just go to maps no one goes to normally and you'll more than likely find one at least.
If you're that worried about being hit just make a Cleric. Heal of any damage done and if you're using Magic Guard just have a Jr Boogie 1 Familiar.