What Is Pantoscopic Tilt & The Need For It In Eyeglasses?

by admin on 08/09/2010

Pantoscopic tilt.  What the whaaa?  Exactly.  Despite the fact that many have never even heard the term, it truly does exist, and it refers to an angle when it comes to eyeglass frames.

When glasses are fitted and adjusted to any patient, an optician must pay close attention to what is known as the pantoscopic tilt of the eyewear.  Before even adjusting, it is a great practice to pay close attention to the tilt of the eyewear prior to any readjustment, and I will explain why. First, however, let’s get into the simple meaning of the pantoscopic tilt.

One of the easiest ways to understand pantoscopic tilt is to grab a pair of frames or a complete pair of eyeglasses.  Once you have them, place them on a flat surface, temple tips touching the counter (sitting as though they are on someone’s face).  Next, look at them from the side.  For example, turn the eyeglasses/frames so that if a person had them on, they would look to the right or left of you.  This way, you will observe the eyewear from the side.

From this vantage point, you will notice that the frames are not straight up and down looking at the eye wire, or rim.  Instead, the eyeglasses are sitting at an angle, or tilt.  Most of the time, all eyewear must sit on a patient with a certain amount of angle toward the face from the lower rim.  This lower rim tilt toward the cheeks is called pantoscopic tilt, and it is needed in order for patients to rotate the eyes from distance to reading without having difficulty, looking under the glasses and in order to maintain vertex distance.

Other than the pantascopic tilt, there is another tilt called retroscopic that fits a patient just the opposite.  Instead of the lower rims going toward the cheeks, retroscopic tilt goes away from the face.  This could cause the patient’s vision become problematic as retroscopic tilt does not adhere to the vertex distance needed in prescriptions, thus creating refractive errors.

Always keep this in mind when a patient needs an eyewear adjustment due to the fact that eyewear could have been sat or stepped on, thus, altering the correct pantoscopic tilt.  As a matter of fact, if a patient comes in for a new set of eyewear, once the glasses are completed, if the customer has the old pair of eyeglasses, request that they bring that old pair in for the fitting.  This way if there is a problem with the vision once frames are fitted, the one thing that you can compare are the pantoscopic tilts!

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