deadeye

thumb|left|A triple deadeye without a lanyard A deadeye is an item used in the standing and running rigging of traditional sailing ships. It is a smallish round thick wooden (usually lignum vitae) disc with one or more holes through it, perpendicular to the plane of the disc. Single and triple-hole deadeyes are most commonly seen. The three-holed blocks were called deadeyes because the position of the three holes resemble the eye and nose sockets of a sheep's skull.

thumb|right|A single deadeye (or bull's eye) used to change the direction of a line, in this case a clewlines and buntlines|buntline on Prince Williams fore-topgallant. Single deadeyes (or '''bull's eyes') are used to guide and control a line and, particularly in older vessels, to change its direction. More modern systems would use a block for this purpose but in traditional rigs with many lines to deal with, designed when blocks were relatively expensive to make, a deadeye provided an acceptable compromise. When blocks came into common use for adjusting running rigging, deadeyes continued to be used for tensioning standing rigging.