An intrastromal corneal insert, including an element with the shape of an arc of circumference with a predetermined angular extension (A) less than 360° and made in inert or biocompatible polymer material, intended to be implanted in the stroma of the cornea for correcting sight defects, said element with the shape of an arc of circumference including first through holes, suitable for allowing organic fluids to pass, having the respective axes perpendicular or substantially perpendicular to the plane defined by the element with the shape of an arc of circumference, and second through holes, suitable for allowing organic fluids to pass, having the respective axes parallel or substantially parallel to the plane defined by the element with the shape of an arc of circumference the first through holes are arranged alternately with the second through holes, and/or the first through holes are in communication with the second through holes.