A system may include finger devices. A touch sensor may be mounted in a finger device housing to gather input from an external object as the object moves along an exterior surface of the housing. The touch sensor may include capacitive sensor electrodes. Sensors such as force sensors, ultrasonic sensors, inertial measurement units, optical sensors, and other components may be used in gathering finger input from a user. Finger input from a user may be used to manipulate virtual objects in a mixed reality or virtual reality environment while a haptic output device in a finger device provides associated haptic output. A user may interact with real-world objects while computer-generated content is overlaid over some or all of the objects. Object rotations and other movements may be converted into input for a mixed reality or virtual reality system using force measurements or other sensors measurements made with the finger devices.