I'm assuming you have a polyurethane/film finish on your floor? If so, to get a decent looking floor you do have to strip the current layer of poly. If you simply scuff-sand the current poly and sand the current patches of bare wood, then when you apply another coat of urethane you'll have uneven coloration on your floor.
If the uneven color is not a concern, then the easiest way to do light sanding is to "screen" the flooring. You can rent a machine from a rent-all, and instead of using sandpaper to take down the floor to bare wood it uses a pad to just scuff up the surface of the poly. Just enough to give tooth so your next application of poly will adhere to the current film on your floor.
It creates much less dust than a full sanding, but again, it's a compromise.
If your floor has an oil finish on it, simply clean up the bare patches and you can renew the il with a simple wipe-on/wipe-off application.