1. A method for optically communicating, from a user to a laser tracker, a command to control operation of the laser tracker with steps comprising: providing a rule of correspondence between each of a plurality of commands and each of a plurality of positions, each position being a three-dimensional coordinate; selecting by the user a first command from among the plurality of commands; moving by the user a retroreflector to a first position from among the plurality of positions, wherein the first position corresponds to the first command; projecting a first light from the laser tracker to the retroreflector; reflecting a second light from the retroreflector, the second light being a portion of the first light; obtaining first sensed data by sensing a third light, the third light being a portion of the second light; determining the first command based at least in part on processing the first sensed data according to the rule of correspondence; and executing the first command with the laser tracker.