A method for bonding at low or room temperature includes steps of surface cleaning and activation by cleaning or etching. This invention avoids the difficulties and risks of existing techniques, providing protection to the cataract-operated eye and improving natural protection in eyes with retinal neuro-degeneration, through the simple application of a contact lens. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer. Whenever appropriate, cryptographic schemes are applied to protect the system.