Abstract: A lighting device for an operational field of the “cast shadow” type, which is particularly useful for but not limited to field of dental surgery, includes a lighting head which is fed with light by at least one cord of optical fibers for directing the light produced by a light generator placed at a distance from the lighting head. The light generator is provided with a mechanical system for moving an inlet end piece of the cord away from or closer to a lamp which serves as the light generator. The lighting head is further configured to project the approximately rectangular light spot which is required for illuminating the operational field onto the work zone.