OCULUS Optikgeräte Gesellschaft mit beschränkter Haftung
Model
65000
Device description
The PARK 1 combines three measuring functions in one unit.Auto-RefractometerAn infrared light source projects measuring light onto the retina of the eyefrom where it is reflected back to the shutter location. Sensitive sensorchips, or CCD cameras now register the deviation of the reflected light fromthe shutter location. The deviation depends on the ametropia. From that, anintegrated microcomputer calculates the ametropia in D, based on thesphere, cylinder and cylinder axis position.1 Measuring ocular / Patient eyepiece 4 Chin rest2 Keratometer ring 5 Marking for the eye height3 Pachycam camera glass coverKeratometerTo determine the curvature of the cornea, a reflected image of the corneais captured by a camera sensor and is measured.The reflection of test marks and of a ring is used as the reflected image.This allows the central radii of the cornea to be determined.PachymeterThe pachymetry principle uses Scheimpflug images of the cornea, whichare analysed by a built-in computer.600 Absolute data points are evaluated with the Scheimpflug image. Themeasuring range lies on a 4 mm slit through the apex.The slit light illuminates a sectional plane from the front surface of the corneato the back surface. The transparent cells of the cornea scatter the slitlight such that the sectional plane appears as if it were self-luminous.This is captured at an angle of 45° through the pupil by a camera, wherebythe image plane of the camera is also tilted 45° to the optical axis of thecamera lens, in order to sharply focus the light-scattering cornea planeonto the image plane of the camera (Scheimpflug image).Thanks to this arrangement, sharp sectional images of the cornea can be attained.
A manually-operated ophthalmic device used to measure the refractive error of the eye (the inaccuracies of focusing of light upon the retina); typically the measurements are made in dioptres (the reciprocal of the focal length of the lens expressed in metres). Using this information the optometrist can calculate the lens prescription needed to correct the patient's refractive error. With advanced instruments the measurements are made automatically with printed verification.