TESTING APPARATUS

摘要

A tonometer for measuring the intra-ocular pressure of an eye in which a pulse of fluid is projected towards the cornea of the eye to distort the corneal surface by the pressure of the pulse, thedistortion in the corneal surface being detected by a change in the reflection of light directed onto the cornea. A constant volume chamber (96) forms part of the fluid delivery system, with inlet means (71) by which fluid under pressure can be supplied to the chamber when a fluid pulse is required. A lens assembly (110, 112) is fixed in the chamber wall for directing light toward an eye under test, and a tube (108) extends coaxially through the lens assembly to protrude internally into the chamber, where it is closed-off at (114) but includes a plurality of apertures (118) in the internally protruding wall section to permit the controlled passage of fluid from the chamber into the tube.