Since the beginning of time you have not been able to cast/commune "blindness" on someone that has dirt in their eyes. For some reason I just had the urge to actually inquire about it tonight... I guess I just always accepted it for one reason or another. Anyway.
Why can't someone who has dirt in their eyes also be blinded?

The obvious explanation (from a fellow programmer's view) is that dirt kicking, blindness, flash, etc. just simply put an is_blind flag on the person with the hourly value that is rolled at the time of success, and it's simply decremented every tick. That flag is checked by commands like look, and whatever else applicable in combat.. etc.

Here's how I see it logically:

When you have dirt in your eyes, essentially the dirt is causing you to clench your eyelids together tightly, along with the effects of making them tear, and blurring everything... so even if you could open your eyes, you wouldn't be able to see.

However, with "blindness" and "flash" they are temporarily damaging your retinas, or however you want to look at it, so that you can't see, even if your eyes were open.

The way the game handles it is that if someone is blinded by dirt you can't commune/cast blindness on them, and visa versa.

Should you not be able to mix and match these effects? I think you should be able to cast blindness on someone who's eyes are closed (dirted) because that is having some sort of physical augmentation on the eyes, independant of whether or not they're open; however, the Conjurer 'flash' spell is relying on that person to have their eyes opens (hence the Group warning "Cover your eyes, everyone.")

So, in short. You should be able to cast/commune blindness on someone who is dirted, but you shouldn't be able to blind them further by way of flash. Finally, you should be able to kick dirt in someone's eyes *all* the time. If they're blind, then maybe it'll just scratch them. If they're not blind, it'll blind them. Obviously someone is not going to use "dirt kicking" if their target is already blinded, but the game takes away that option. I know I'd love to spam dirt toward the end of a battle, hoping I kill someOne with "scratches" from dirt

Does any of that make sense? If there's a reason why it is the way it currently is, could you please post a reply as to your reasoning? Thanks for your time.

-Zepachu