A controllable optical assembly (199, 599) with a variable optical power and/or a variable beam deflection, the optical assembly comprises - a first cover member and a second cover member, wherein one of the first and second cover members is a transparent cover member, and the other of the first and second cover members is a transparent or reflective cover member, - a transparent, deformable, non-fluid body sandwiched between the first and second cover members, so that the first and second cover members and non-fluid body constitute a lens or a light deflector with an optical axis intersecting the non-fluid body and the first and/or the second transparent cover members, - one or more actuators arranged to generate a controllable bending and/or tilt of at least the first cover member dependent on a control signal, where the control signal is obtainable from first and second measurement signals, - first and second sensors arranged to provide the first and second measurement signals so that the measurement signals are indicative of the bending and/or tilt of at least the first cover member, and wherein the first sensor is an optical sensor and the second sensor is a deformation sensor, - wherein the optical sensor comprises a light source arranged to transmit a light beam so that the light beam is affected by the bending or tilt of the first and/or the second cover member, and where the sensor comprises a light detector arranged to measure a change of the light beam relating to the bending and/or tilt, and - wherein the deformation sensor comprises a piezo electric sensor element connected to the first cover member, and/or - wherein the deformation sensor is connected to a surface of the one or more actuators. - a first cover member and a second cover member, wherein one of the first and second cover members is a transparent cover member, and the other of the first and second cover members is a transparent or reflective cover member, - a transparent, deformable, non-fluid body sandwiched between the first and second cover members, so that the first and second cover members and non-fluid body constitute a lens or a light deflector with an optical axis intersecting the non-fluid body and the first and/or the second transparent cover members, - one or more actuators arranged to generate a controllable bending and/or tilt of at least the first cover member dependent on a control signal, where the control signal is obtainable from first and second measurement signals, - first and second sensors arranged to provide the first and second measurement signals so that the measurement signals are indicative of the bending and/or tilt of at least the first cover member, and wherein the first sensor is an optical sensor and the second sensor is a deformation sensor, - wherein the optical sensor comprises a light source arranged to transmit a light beam so that the light beam is affected by the bending or tilt of the first and/or the second cover member, and where the sensor comprises a light detector arranged to measure a change of the light beam relating to the bending and/or tilt, and - wherein the deformation sensor comprises a piezo electric sensor element connected to the first cover member, and/or - wherein the deformation sensor is connected to a surface of the one or more actuators.