I remember when I was a kid and my dad showed me a memo he had gotten from the IT guy at his work instructing users on the proper technique for cleaning their mouse balls. It was funny because it went into great detail about the entire process of cleaning them in a way that made the author appear to be blissfully ignorant of the fact that, to most lay persons at the time, it seemed to be describing a very different act than what he had intended.
Today, many of us can look back - perhaps with nostalgia - on the days when our mice had balls. Some of us may even recall the annoyance that dirty mouse balls could cause. The pointer just wouldn't move exactly where you wanted it to. Often, it would skip right over that spot no matter what you did. That is, until you turned it over, rotated the cover 45 degrees counter-clockwise, removed the ball, and then scraped the gunk off of the two rollers that corresponded to the X- and Y-axes.
Well, friends, I am here to tell you that optical mice are not immune to the accumulation of detritus and debris. Why, just a few minutes ago I was getting very irritated because the optical mouse I've had for about 15 years was not as responsive as it used to be. I had tried replacing the battery and reconnecting it to the base station, but to no avail. It turns out that the hole in the bottom where the laser and optical sensor are housed had become partially filled with dog hair. Yes, dog hair. Gross.
I got a Q-Tip, twirled it around in the hole a few times, pulling out a little more hair each time, and then blew out the rest. Now my optical mouse is as responsive as it was when I first got it.
If your mouse doesn't move like it used to, now you can do something about it: Simply turn it over to expose the hole in its underside, moisten one end of a Q-Tip, stick it in the hole, and twirl it around a few times until nothing else come out. Then blow into the hole a couple of times for good measure. Your mouse will thank you.