The present invention relates to a wearable device for acquiring physiological information of a subject. To combine the advantages of a contact sensor and a contactless sensor, the wearable device comprises an optical emitter (10) for emitting light into the subject's skin, an optical sensor (20) for receiving light scattered back from the subject's skin in response to the emission of light into the subject's skin, the received light representing or allowing the derivation of physiological information of the subject, and a carrier (30) for being held at the subject's skin and for carrying said emitter (10) and said sensor (20) such that a light receiving area (12), at which the emitted light enters the subject's skin, substantially corresponds to a light reflecting area (22), at which at least part of the scattered light leaves the subject's skin and is received by said optical sensor, the optical sensor (20) is arranged between the optical emitter (10) and the light receiving area (12) and is at least partially transparent for the light emitted by the optical emitter or the optical emitter (10) is arranged between the optical sensor (20) and the light reflecting area (22) and is at least partially transparent for the light reflected from the light reflecting area.