Visual conversion disorder in a harbor pilot leading to sudden loss of control of a large vessel.

We describe an accident caused by the rapid onset of visual impairment in a ship's pilot, who was subsequently diagnosed as having visual conversion disorder (hysterical blindness). This case is documented to draw attention to the unusual cause of sudden incapacitation in transport crew and the consequential threat to transportation safety. Because sudden visual impairment incidents caused by conversion disorder are isolated and rare, they may be under-reported in the scientific literature. While it is unlikely that current systems for medical screening could anticipate and/or prevent crew incapacitation due to conversion disorders, this condition should be borne in mind when consulted by crew who report otherwise unexplained physical symptoms in the context of high levels of personal stress. It should also be considered when investigating possible medical incapacitation in transportation incidents or accidents.