Abstract: An applanation tonometer comprises a housing, a rod accommodated in the housing and carrying a contact disk adapted to interact with the corneal surface in order to exert force thereon, a unit for measuring the force applied to the cornea, a means for registering the instant of time when the diameter of an applanation circle on the corneal surface formed due to the effect of a force applied thereto reaches a preset value, and a recording unit. The registering means is made as a sleeve arranged coaxially with the rod carrying the contact disk and traversably along the rod axis, and a contact set electrically connected to the recording unit and mechanically associated with the traversable sleeve. An additional sleeve is traversable, set coaxially with the traversable sleeve of the registering means, and the end of said additional sleeve is concave-shaped.