Park 1

The PARK 1 combines three measuring functions in one unit. Auto-Refractometer An infrared light source projects measuring light onto the retina of the eye from where it is reflected back to the shutter location. Sensitive sensor chips, or CCD cameras now register the deviation of the reflected light from the shutter location. The deviation depends on the ametropia. From that, an integrated microcomputer calculates the ametropia in D, based on the sphere, cylinder and cylinder axis position. 1 Measuring ocular / Patient eyepiece 4 Chin rest 2 Keratometer ring 5 Marking for the eye height 3 Pachycam camera glass cover Keratometer To determine the curvature of the cornea, a reflected image of the cornea is 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. Pachymeter The pachymetry principle uses Scheimpflug images of the cornea, which are analysed by a built-in computer. 600 Absolute data points are evaluated with the Scheimpflug image. The measuring range lies on a 4 mm slit through the apex. The slit light illuminates a sectional plane from the front surface of the cornea to the back surface. The transparent cells of the cornea scatter the slit light 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, whereby the image plane of the camera is also tilted 45° to the optical axis of the camera lens, in order to sharply focus the light-scattering cornea plane onto the image plane of the camera (Scheimpflug image). Thanks to this arrangement, sharp sectional images of the cornea can be attained.