A device (1; 1') for the detection of the profile of a rolling surface of a rolling body, in particular a tread (TR) of a tyre for a vehicle (TY), the device including a light source and an optical assembly configured for processing a first light beam (I) emitted by said light source, wherein: - said first light beam (I) is a planar light beam having a divergent course, - said light source is configured for emitting said first light beam (I) towards said optical assembly , - said optical assembly includes a first refractive member and a second refractive member configured for collimating at least one portion of said first light beam (I, R1) incident thereon into respective measurement beams (RF10, RF12) that are directed towards a measurement section (MS) of said device (1; 1') to impinge upon said rolling surface (TR), - said optical assembly further includes a first reflecting member , wherein said light source is configured for emitting said first light beam (I) towards said first reflecting member , said first reflecting member being configured for reflecting said first light beam (I) into a second light beam (R1) incident upon said refractive members , wherein said first and second refractive members include a first Fresnel lens and a second Fresnel lens , and in that said first and second refractive members are arranged on opposite sides with respect to said light source so as to intercept a respective peripheral band (PB) of said second light beam (R1) ; and wherein said measurement beam includes said peripheral bands (PB) collimated (RF 10 , RF 12 ) by said first and second refractive members and a portion of said second light beam (R1) that traverses an area comprised between said first and second refractive members . - said first light beam (I) is a planar light beam having a divergent course, - said light source is configured for emitting said first light beam (I) towards said optical assembly , - said optical assembly includes a first refractive member and a second refractive member configured for collimating at least one portion of said first light beam (I, R1) incident thereon into respective measurement beams (RF10, RF12) that are directed towards a measurement section (MS) of said device (1; 1') to impinge upon said rolling surface (TR), - said optical assembly further includes a first reflecting member , wherein said light source is configured for emitting said first light beam (I) towards said first reflecting member , said first reflecting member being configured for reflecting said first light beam (I) into a second light beam (R1) incident upon said refractive members , wherein said first and second refractive members include a first Fresnel lens and a second Fresnel lens , and in that said first and second refractive members are arranged on opposite sides with respect to said light source so as to intercept a respective peripheral band (PB) of said second light beam (R1) ; and wherein said measurement beam includes said peripheral bands (PB) collimated (RF 10 , RF 12 ) by said first and second refractive members and a portion of said second light beam (R1) that traverses an area comprised between said first and second refractive members . <EOS>