| 摘要 |
An applanating tonometer has respective means (18, 26) for transmitting a measurement beam through an applanating element (44) onto the eye of a subject and detecting the illumination reflected therefrom as a measure of the degree of applanation by a contact face (46) of the element. Applanating force and reflected illumination data are collected as the applanating force progressively builds until the contact face of the applanating element is fully applied to the eye. By interpolation of the collected data the applanating force for a predetermined smaller contact area is then derived. In this way a more accurate reading can be obtained. Means may be provided to compensate for any dynamic forces acting at the instant of applanation of the predetermined smaller area. An arrangement is also provided to monitor alignment of the tonometer with the eye, using a monitoring light source (24) from which illumination is directed along conjugate paths to form a light pattern on the retina which is dependent upon the alignment of the tonometer with the eye.
|
