We briefly review the current literature where optogenetics has been used to study various aspects of astrocyte physiology in vitro and in vivo. This includes both genetically engineered Ca(2+) sensors and effector proteins, such as channelrhodopsin. We demonstrate how the ability to target astrocytes with cell-specific viral vectors to express optogenetic constructs helped to unravel some previously unsuspected roles of these inconspicuous cells.