The invention relates to a method for determining an optical property 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 by the said sample；detection of N optical signals, backscattered by the sample, each optical signal emanating from the surface of the sample at a distance, termed the backscattering distance, from the said elementary illumination zone, N being an integer greater than or equal to 1, so as to form as many detected signals；determination of at least one optical property of the sample, by comparison between:a function of each signal thus detected；and a plurality of estimations of the said function each estimation being carried out by considering a predetermined value of the said optical property,the method being characterized in thatduring the said detection step, at least one backscattering distance is less than 200 μm.
