| 摘要 |
<p>The size of an optic nerve head (20) of a test eye (26) is determined with the aid of an optical imaging arrangement (28, 32) for focussing an image of the optic nerve head on a displaceable imaging means (30). A reference position is established for the imaging means, the reference position being a position of focus for an emmetropic eye. A value of radius of curvature appropriate to a cornea of the test eye (26) is established. Displacement of the imaging means (30) is determined from the reference position to a position in which the optic nerve head (20) is in focus on the imaging means. Data are established relating magnification of images and displacement of the imaging means (30) from the reference position to positions of focus on the imaging means, as a function of corneal radius of curvature. The displacement of the imaging means (30) from the reference position for the test eye (26) is applied to the data and a value is derived of the magnification in accordance with the appropriate corneal radius of curvature.</p> |
