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Nowadays, prescription progressive glasses are gaining more and more popularity among the glasses wearers. And if you have one pair of prescription progressive glasses at hand, you can see clearly at different distances without changing glasses. For example, you can use the top potion for far distance use and when you drop your gaze downward, you can also read and do fine work comfortably.
Prescription progressive lenses, also called Progressive Addition Lenses (as PAL) include three fields of vision. The top portion of the lens is for distance-vision use, narrowing to the lower middle for mid-range which can be used for intermediate distance, finally to the bottom portion for the near-vision or reading. And they have a gradient of increasing lens power which is more easily to get adapted compared with other multi-focal lenses such as bifocal. Besides, almost all the lens materials are available for prescription progressive glasses such as regular plastic, glass, polycarbonate, high-index or photochromic types.
In order to make sure that we can wear prescription progressive glass comfortably, it is not enough to get the knowledge of progressive lenses. We should also know some aspects we should take into consideration for prescription progressive glasses.
The first factor to consider while purchasing prescription progressive glasses should be the frame choice. Generally speaking, it is recommended to choose a frame type with larger size (with the frame height higher than 28mm), which allows your eyes to have more areas to get used to the different powers. Conversely, if you choose a frame with small frame height, it will result in a very small reading area which will also cause discomfort for your vision. Except for the frame height, adjustable nose-pads are also considered as one of the best choice for prescription progressive eyeglasses since you can change the location of the glasses by adjusting the nose-pads to make it comfortably. For example, if you find the segment for your prescription progressive is a bit lower than you expected, you may push the nose pads to get close slightly to raise the eyeglasses on the nose.
The other important factor for prescription progressive glasses should be the PD value. Since the multiple viewing fields for prescription progressive glasses are adjusted on the basis of the PD supplied, progressive lenses are the most sensitive glasses for the correct PD. When you go to the optician to have your eyes examined, in order to make your prescription progressive more accurately, you’d better ask your doctor to provide the mono PD value for each eye. |
