摘要 |
<p>A tonometer which comprises a casing adapted to be hand-held, said casing including an optical system (10,26) for forming a viewable image of the cornea of the eye (28), optical detecting means (32,34A,34B) for determining when the tonometer, which is by hand slowly moved around, is axially aligned with the cornea, means (40-58) for firing a controlled puff of air on to the cornea when a condition of stabilised alignment is determined, and circuitry responsive to the outputs of the optical detecting means (32,34A,34B) for determining when a change in image contrast occurs due to applanation of the cornea, said puff firing means and said circuitry being adapted to measure the pressure at the eye (28) when applanation is detected. The tonometer may take the form of a portable system in which at least some of the components are contained in a hand-held unit (100). Alternatively the tonometer may be bench-mounted.</p> |