An optical device for the verification of pile-driving characterised in that it comprises: - a supporting structure, comprising an inertial system configured to eliminate and/or correct movements of the terrain due to the driving process of a pile, where the supporting structure comprises: ∘ a camera, configured to capture images of the surface of the pile; ∘ an articulated arm, which in turn comprises a point of reference; ∘ a sensor-illuminator, configured to illuminate the surface of the pile and the point of reference by means of a laser illumination pattern, likewise to measure: ▪ a distance from said sensor-illuminator to a contrast strip adhered to the surface of the pile, and; ▪ a distance from the sensor-illuminator to the projection of the point of reference illuminated by the laser light on the surface of the pile; - equipment for the processing of the images captured by the camera and of the distances measured by the sensor-illuminator; and - a monitor, configured to display the processed images, captured by the camera, containing the information about the distances measured by the sensor-illuminator; where the processing equipment is configured so as to measure, on each image captured by the camera, a distance between the contrast strip and the point of reference and to calculate the actual distance on the pile between the contrast strip and the projection of the point of reference on the surface of the pile. - a supporting structure, comprising an inertial system configured to eliminate and/or correct movements of the terrain due to the driving process of a pile, where the supporting structure comprises: ∘ a camera, configured to capture images of the surface of the pile; ∘ an articulated arm, which in turn comprises a point of reference; ∘ a sensor-illuminator, configured to illuminate the surface of the pile and the point of reference by means of a laser illumination pattern, likewise to measure: ▪ a distance from said sensor-illuminator to a contrast strip adhered to the surface of the pile, and; ▪ a distance from the sensor-illuminator to the projection of the point of reference illuminated by the laser light on the surface of the pile; ∘ a camera, configured to capture images of the surface of the pile; ∘ an articulated arm, which in turn comprises a point of reference; ∘ a sensor-illuminator, configured to illuminate the surface of the pile and the point of reference by means of a laser illumination pattern, likewise to measure: ▪ a distance from said sensor-illuminator to a contrast strip adhered to the surface of the pile, and; ∘ an articulated arm, which in turn comprises a point of reference; ∘ a sensor-illuminator, configured to illuminate the surface of the pile and the point of reference by means of a laser illumination pattern, likewise to measure: ▪ a distance from said sensor-illuminator to a contrast strip adhered to the surface of the pile, and; ▪ a distance from said sensor-illuminator to a contrast strip adhered to the surface of the pile, and; ▪ a distance from the sensor-illuminator to the projection of the point of reference illuminated by the laser light on the surface of the pile; - equipment for the processing of the images captured by the camera and of the distances measured by the sensor-illuminator; and - a monitor, configured to display the processed images, captured by the camera, containing the information about the distances measured by the sensor-illuminator;