The subject matter discloses a device for measuring biological properties of an examined tissue, the device comprising at least one light source configured and operable to illuminate the examined tissue with light radiation of one or more wavelengths at a certain light illumination direction; and a light detector located at a same side of said examined tissue and configured and operable to receive light components of said one or more wavelengths reflected from the examined tissue in response to the illuminated light radiation at a certain light detection direction, and to generate measurement data indicative thereof; at least one of said light illumination direction and detection direction is positioned at an angle of at least 20 relative to an imaginary line perpendicular to the examined tissue or form an angle of at least 20 between the light illumination direction and detection direction.