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How to center progressive glasses

It is important that the glasses we wear are positioned on the face properly and that the eyes remain clearly positioned on the inside of the frame. In case of glasses with progressive lenses it is useful to know that they possess three different viewing zones, one for far, near and that for the intermediate area. There are two axes on which the progressive lenses should be centered: height and width. 1. HEIGHT For a correct assembly of progressive lenses it is important that the height of the frame does not fall below of 30mm (in our website to buy all the frames with progressive lenses meet this parameter) to have precisely the three distinct zones of vision and to avoid so that the passage from one to the other is too rapid and may be difficult, especially for those who wear this type of lenses for the first time. During the mounting, in the centering zone for distance vision (high part of the lens), it is left approximately 11/13 mm in order to allow a small slack in centering. When glasses are worn, the support of the nose, can be different from person to person in fact the shape of the nose or the support of the rods in the ears is extremely subjective, so it is a useful practice to position itself in front of the mirror with the worn glasses and see if your eyes positioned in the frame are compatible with this space (about 11 / 13mm) from the top edge interior; to better explain it is correct to say that the eyes should occupy about one-third of \'total height, thus ensuring the vision in the other areas. The above may be useful for all those people who are going to get close to a major purchase like glasses with multifocal lenses (progressive) in fact trying three or more frame models we already have a \'precise indication on the functionality of the same, and since the latter can be suitable. If a indossandone, we realize that the eyes are going to be placed at the bottom or are too close to the center is possible that this model is not very suitable for us, even if, at a later time is always possible to make adjustments. As for all of the frames control systems you should read the previous article entitled: ADJUSTMENT OF GLASSES 2. WIDTH Regarding the width, the lenses should be centered individually according to the interpupillary distance of the subject which will use \'the device. That is why we always ask to check that in your recipe is shown this measure to center of the lenses. It \'a very important measure in order to achieve a progressive eyewear that can fully exploit the quality of the internal geometry lenses. If it is not indicated in eye prescription, you may have also written about some other document, even older, as it is a value that does not change in adults. If you have turned to an eye doctor for a prescription, he frequently releases between documents a piece of paper like a receipt, on which is written at the bottom of PD and a number that\'s what we need.

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