An optical sensing apparatus (10), a corresponding optical sensing method and a corresponding computer program configured to sense a property of a living being are provided. The optical sensing apparatus (10) comprises a contact surface (20) configured to be brought into contact with the skin (5) of the living being, a first optical sensor unit (30； 630) for providing a first optical signal and a second optical sensor unit (40； 640) for providing a second optical signal, wherein the first optical sensor unit (30； 630) and the second optical sensor unit (40； 640) are arranged on the contact surface (20) at a distance from each other, wherein the first optical sensor unit (30； 630) has a different protrusion length (50) from the contact surface (20) than the second optical sensor unit (40, 640). The optical sensing apparatus (10) allows a more reliable determination of a property of a living being.
