Some wireless mice are fairly lightweight. My preference is for a wireless mouse because even gentle drag from the cord is distracting, and also the best tracking mice ( Logitech Darkfield ) are only available as wireless. These things work flawlessly on glass, which makes for a lovely low friction surface.
For carpel tunnel complaints, they say the best thing is to vary your input periodically, so running a mouse as well as a graphics tablet or trackpoint might help. I know one person who trained themselves to use a mouse with their left hand (it took them a week, they tell me) so they could swap every hour.