07 Which of the following is not an option for a patient wanting budget PPLs selecting a frame with a pantoscopic tilt
of 3[degrees]that cannot be adjusted?
Following a US Government paper that indicated how prescription eyewear with acute face form angles (> 12[degrees]) and pantoscopic tilts
with measured angles (> 18[degrees]) could induce distortion, headaches and dizziness, Wiley Talon demonstrated that it was able to meet the new stringent requirements thanks to its shield with near vertical pantoscopic tilt
The company's first issued patent has broad coverage and addresses the combination of wavefront measurements with obtaining biometric parameters necessary to make customized eyeglasses, such as the measurement of a patient's pupil size, pupil distance, vertex distance, pantoscopic tilt
and other fitting parameters.
Children have flatter faces and longer eyelashes and required pantoscopic tilt
is typically zero degrees, compared to adults who generally vary between 8-12[degrees]; therefore, care must be taken to ensure the lower rim of the frame does not rest against the cheeks.
It is usual for the younger child to have a higher cheek position and, therefore, the dispenser needs to pay attention to the pantoscopic tilt
, angle of side and depth of the frame to ensure a suitable fit.
Of course, snooker players often choose the custom-designed high fitting frames with adjustable pantoscopic tilt
made popular by Dennis Taylor.
With regard to the sides, it is necessary to consider the pantoscopic tilt
, side length, length of drop, temple and head width.
The angle of pantoscopic tilt
will often be lower on a child's frame and this should also be considered when specifying vertical centres.
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 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.