What wears out a bench grinding stone. Grooves good or bad?

I use my bench grinder for flat grinding mostly. I use the edge of the stone to debur occasionally. It's kind of rounded on both edges and flat in the middle for flat grinding. But I try not to create grooves and to keep parts moving.
In a shop I'm working in I've got full rein, the owners aren't real hands on, as long as the work gets done they seem happy but I want to take care of it. The last folks working there wore a real groove a little to the right of the center. It's only used to debur small round stock and I've been trying to even out the face but without being able to smoothly move side to side I'm making small grooves. Am I making things worse? I've got to get things done quickly it pays on production, but I want to take care of their things. I get a feeling the last folks just did what was easy and fast ( putting the part at an angle in the middle and applying a lot of pressure) which started the problem.

How do you use your bench grinder? Will running a bench grinder without anything on one side damage it?
I took the unused wire wheel off to put on a cut off wheel but I need a space of some kind an I didn't replace it because it gets in the way and it would have been a hassle to take off twice, I figured it was made to handle a variety of weight including none.

Grinding wheels need to be dressed from time to time for several reasons and it is not hard to do with the proper tools. You can use a star or disk wheel dresser or a
diamond dresser.

Dressing the wheel will get rid of groves, remove loaded material, and expose new and sharp abrasive particles. It will restore the wheel to a like new condition but it will be a little smaller in diameter.
http://www.youtube.com/watch?feature=endscreen&v=k2HxbRjRpkE&NR=1

http://www.youtube.com/watch?v=BkyLua8t10M&feature=related

Hi Greg, as ciladog has shown, there are tools you can get/buy to dress stones. I don't have them available to me and I too get xxxxxx off when I find someone has grooved the xxxx out of a stone in the workshop. With careful application you can work the grooves out with normal use, as in just keep using the wheels but work each side, with a view to achieving a flat face, until the groove/s are gone. If you need to use the full face of the wheel, then you can dress the face using something like a section of leaf spring, sliding back and forth until the face is flat. Again, as noted, the wheel will be smaller, so check the tool rest gap. You'll probably need to adjust it in.

Thanks. I've got a dressing tool, I'll just keep wear out the stone until it's time to fix it. And then I'll start worrying about avoiding grooves.