Investigations were carried out in 4 rabbits. The right eyes of the animals were experimental, the left eyes--tentative (radial keratotomy with 8 incisions, maximum depth of the central zone--3.0 mm in diameter). Mechanical trial of isolated corneas with a scleral rim were made 6 months after surgery by means of a trial machine "Instron-1122" and a special clamping device. After trial, the specimens were investigated by a method of scanning electron microscopy. As a result of mechanical action, the rupture of the cornea in the zone of contact with the punch was recorded in all cases. In the control eyes, the area of the cornea was practically the same as the zone of the punch pressure on the cornea. In tentative eyes, the rupture was connected with keratotomy scars in all cases. The values of destructive load, transference of the punch at the moment pattern destruction and destructive tension along the punch contour were determined. The results obtained have shown that anterior radial and not crossing the limbus incisions in the cornea produce changes in mechanical characteristics of the cornea: in the sites of keratotomy scars, "conditionally" weak places of the corneoscleral coat are formed, the probability of breaks and tears of which in contusions of the increases.