Optical mouse only moves with great effort or erratically. (Especially the Logitech M500)

My Logitech M500 mouse has the annoying habit of sucking up pet hair into the laser hole. When this happens my cursor stops moving smoothly. Sometimes I lose a directory entirely and other times it takes a lot of physical movement to get much cursor movement.

To fix it get a bright light, reading glasses, and some tweezers and remove any hair you find in your mouse's laser hole. It just takes a single hair to make it stop working very well.