During the filming of the Ludovico technique scene, McDowell scratched a cornea, and was temporarily blinded. The doctor standing next to him in the scene, dropping saline solution into Alex's forced-open eyes, was a real physician present to prevent the actor's eyes from drying. McDowell also cracked some ribs filming the humiliation stage show. A unique special effect technique was used when Alex jumps out of the window in an attempt to commit suicide and the viewer sees the ground approaching the camera until collision, i.e., as if from Alex's point of view. This effect was achieved by dropping a Newman-Sinclair clockwork camera in a box, lens-first, from the third storey of the Corus Hotel. To Kubrick's surprise, the camera survived six takes.