A device for optical inspection of parisons, comprising: - an illuminator including a light source configured to emit a beam of light directed towards a parison located at an inspection position; - a detector including a camera configured to capture an image of the parison located at the inspection position, wherein the parison, at the inspection position, is operatively interposed between the illuminator and the detector, wherein the illuminator includes an emission-polarizing filter configured to intercept the beam of light emitted by the light source and to generate a polarized light beam, and in that the detector includes a receiving polarizing filter configured to receive the polarized light beam, so that the parison, at the inspection position, is operatively interposed between the emission-polarizing filter and the receiving polarizing filter; - a self-learning system; - a processing unit including: a memory including reference data sets (51, 52); a processor programmed to process the image captured by the detector based on the reference data sets (51, 52), in order to derive a diagnostic indication regarding a defectiveness of the parison;, so that the diagnostic indication distinguishes between a with-defect typology of objects and a defect-free typology of objects, the processing unit being trained, by the self-learning system, through samples of objects of the defect-free typology, wherein the processing unit is configured to: - process the image captured by the detector based on the reference data sets (51, 52), in order to derive from the image values of a plurality of image features; - process the values of the plurality of image features to derive the diagnostic indication regarding the defectiveness of the parison; - generate an image reconstructed from the values of the plurality of image features and based on the reference data sets (51, 52); - deriving the diagnostic indication regarding the defectiveness of the parison as a function of comparing the image captured by the detector with the reconstructed image. - an illuminator including a light source configured to emit a beam of light directed towards a parison located at an inspection position; - a detector including a camera configured to capture an image of the parison located at the inspection position, wherein the parison, at the inspection position, is operatively interposed between the illuminator and the detector, wherein the illuminator includes an emission-polarizing filter configured to intercept the beam of light emitted by the light source and to generate a polarized light beam, and in that the detector includes a receiving polarizing filter configured to receive the polarized light beam, so that the parison, at the inspection position, is operatively interposed between the emission-polarizing filter and the receiving polarizing filter; - a self-learning system; - a processing unit including: a memory including reference data sets (51, 52); a processor programmed to process the image captured by the detector based on the reference data sets (51, 52), in order to derive a diagnostic indication regarding a defectiveness of the parison;, so that the diagnostic indication distinguishes between a with-defect typology of objects and a defect-free typology of objects, the processing unit being trained, by the self-learning system, through samples of objects of the defect-free typology, a memory including reference data sets (51, 52); a processor programmed to process the image captured by the detector based on the reference data sets (51, 52), in order to derive a diagnostic indication regarding a defectiveness of the parison;, so that the diagnostic indication distinguishes between a with-defect typology of objects and a defect-free typology of objects, the processing unit being trained, by the self-learning system, through samples of objects of the defect-free typology, - process the image captured by the detector based on the reference data sets (51, 52), in order to derive from the image values of a plurality of image features; - process the values of the plurality of image features to derive the diagnostic indication regarding the defectiveness of the parison; - generate an image reconstructed from the values of the plurality of image features and based on the reference data sets (51, 52); - deriving the diagnostic indication regarding the defectiveness of the parison as a function of comparing the image captured by the detector with the reconstructed image.