Method for determining an optical property (μ a , μ s , μ s ', g) of a sample , comprising the following steps: - illumination of a surface of the sample with the aid of a light beam , so as to form, on the surface of the said sample, an elementary illumination zone , corresponding to the part of the said surface illuminated on the said sample, - detection of N optical signals (52 1 , 52 2 , 52 3 , 52 4 , 52 n ), backscattered by the sample, each optical signal emanating from the surface of the sample, at the level of an elementary detection zone (28 n ), at a distance (D 1 , D 2 , D 3 , D 4 , D n ), termed the backscattering distance, from the said elementary illumination zone, N being an integer greater than 1, so as to form as many detected signals (S 1 , S 2 , S 3 , S 4 , S n ), each elementary detection zone (28 n ) being separated from the said elementary illumination zone , - determination of at least one optical property (p) of the sample, by comparison between: ▪ a function (R 1 , R 2 , R 3 , R 4 , R n ) of each signal thus detected (Si, S 2 , S 3 , S 4 , S n ), ▪ and a plurality of estimations of the said function (R 1,p model , R 2,p model , R 3,p model , R 4,p model , R n,p model ), each estimation being carried out by considering a predetermined value of the said optical property (p), the method being characterized in that - during the said detection step, at least one backscattering distance (D 1 , D 2 ) separating an elementary detection zone (28 1 , 28 2 ) from the said elementary illumination zone , is less than 200 μm. - illumination of a surface of the sample with the aid of a light beam , so as to form, on the surface of the said sample, an elementary illumination zone , corresponding to the part of the said surface illuminated on the said sample, - detection of N optical signals (52 1 , 52 2 , 52 3 , 52 4 , 52 n ), backscattered by the sample, each optical signal emanating from the surface of the sample, at the level of an elementary detection zone (28 n ), at a distance (D 1 , D 2 , D 3 , D 4 , D n ), termed the backscattering distance, from the said elementary illumination zone, N being an integer greater than 1, so as to form as many detected signals (S 1 , S 2 , S 3 , S 4 , S n ), each elementary detection zone (28 n ) being separated from the said elementary illumination zone , - determination of at least one optical property (p) of the sample, by comparison between: ▪ a function (R 1 , R 2 , R 3 , R 4 , R n ) of each signal thus detected (Si, S 2 , S 3 , S 4 , S n ), ▪ and a plurality of estimations of the said function (R 1,p model , R 2,p model , R 3,p model , R 4,p model , R n,p model ), each estimation being carried out by considering a predetermined value of the said optical property (p), the method being characterized in that ▪ a function (R 1 , R 2 , R 3 , R 4 , R n ) of each signal thus detected (Si, S 2 , S 3 , S 4 , S n ), ▪ and a plurality of estimations of the said function (R 1,p model , R 2,p model , R 3,p model , R 4,p model , R n,p model ), each estimation being carried out by considering a predetermined value of the said optical property (p), the method being characterized in that - during the said detection step, at least one backscattering distance (D 1 , D 2 ) separating an elementary detection zone (28 1 , 28 2 ) from the said elementary illumination zone , is less than 200 μm. <EOS>