Abstract: A system is provided for monitoring spacing during working operation between a first vehicle and at least one further self-propelled vehicle. A beam source is on one vehicle (source vehicle). A sensor arrangement on another vehicle (target vehicle) extends along a sensor axis. In a predetermined reference state, with the vehicles having a predetermined reference spacing apart, the beam source radiates toward the target vehicle electromagnetic radiation such that a predetermined sensor-axial reference detection region on the sensor arrangement is irradiated by the beam source. A change in the vehicle spacing results in a change, along the sensor axis, in the position of the detection region on the irradiated sensor arrangement, and thus in a change in the detection state of the sensor arrangement. Based on the detection state which depends on an actual spacing of the source and target vehicles, a spacing signal is generated with vehicle spacing information.

Abstract: The invention relates to a visual aid (50), and more particularly, but not exclusively the invention relates to a visual aid for horses. The visual aid comprises first and second lateral portions (50a, 50b) that are adapted to be worn by a horse. In use the first portion (50a) is located on a lateral side of the head of the horse in front of the left eye of the horse; and the second portion (50b) is located on a lateral side of the head of the horse in front of the right eye of the horse. The result is that the eyes of the horse are drawn towards a distant fixation point of focus, between a virtual frame defined by the lateral portions, and so avoiding the problem of the horse having to lower its head, in order to see and thereby reducing muscle strain on the horse's eyes and neck.