Transparent domes useful for covering at least a lens located on a scope's distal face, taking the form of a single layer membrane affixed to the distal end of the scope, a solid cap attachable to and detachable from the distal end of the scope, or an inflatable and deflatable balloon having an exterior wall for contacting at least the lens at the scope's distal face. Methods for performing diagnostic or diagnostic and therapeutic procedures within bodily cavities including collapsed intestines using transparent domes and scopes.