During an accidental radiation leak that ended in an explosion, the apparatus became fused to Octavius's body. It was later revealed that the radiation (or possibly his own latent mutation) had mutated his brain so that he could control the movement of the arms using his thoughts alone. The tentacles have since been surgically removed from his body, although Octavius retains the power to control them telepathically from great distances. The accident also seemingly damaged his brain (although it was later suggested that what was interpreted as brain damage was, in fact, his mind rewiring itself to accommodate four extra limbs), and the scientist turned to a life of crime, first taking the hospital hostage and calling himself "Doctor Octopus" from the derogatory name that his co-workers had given him. Though Doctor Octopus himself is portly, in poor physical shape, and is near-sighted, with his harness attached he is physically more than a match for Spider-Man. The accident also made his eyes very sensitive to light, requiring him to wear glasses with shaded lenses.