d) Check pantoscopic
tilt and adjust to optimum angle
When using high index or aspheric lenses, it is important to record vertical heights and allow for pantoscopic
angle by lowering the optical centre by 1mm for every two degrees of pantoscopic
Also note the effect of ear position on pantoscopic tilt; the lower the ear position, the greater the tilt.
The facial gauge should be held at a 10[degrees] tilt when taking the measurements to mimic the pantoscopic tilt of the frame when fitted.
They are produced by taking into account parameters such as refractive power, final lens thickness, face-form (dihedral) angle, pantoscopic angle and back vertex distance.
The vertical centration should then be compensated for the pantoscopic tilt of the spectacle frame to ensure that the optical axis of the lens passes through the eye's centre of rotation.
Ensure correct horizontal and vertical centration with pantoscopic
5mm for every 1[degrees] of pantoscopic
angle of tilt.
The technology is an innovation in the personalisation process, which fine-tunes a patient's prescription by calculating three distinct measurements--back vertex distance (the distance between the lens and the eye), pantoscopic
tilt (the angle at which the frame sits on the patient's face) and panoramic angle (the angle of the frame itself).
The company's is simple to use and makes it possible to demonstrate the features of comparative lens products, together with a clear representation of the differences that individual parameters (pupil distance, corneal vertex distance, pantoscopic
tilt and face form angle) have on visual fields.
Three essential measurements are determined: pantoscopic
tilt, vertex distance and face-form angle of the patient's eyewear.
The OC must be repositioned by mm for every 2[degrees] change in pantoscopic