Yes, pupillary distance is a must when you want to buy prescription eyeglasses.
It is a vital part of the prescription. If you get the improper pupillary distance, you may suffer from headache, double vision, astigmatism, strabismus dispersion,or even the change of the positions of your eyes. Your vision can't be corrected properly, either.
They have no relation with the prescription. But they are necessary when you buy the prescription eyeglasses. They are important because they decide whether you will have the suitable eyeglasses. If you have the suitable eyeglasses, you will feel comfortable. That is very important when you wear the eyeglasses. You could know your pupillary distance after the eye exam.
Yes, absolutely. The distance between the centers of your pupils is called pupillary distance, whose typical range is between 57 and 65 mm. I mean, you look into the distance with your eyes looking straight ahead, while the distance changes, your eyes converge an average of three millimeters, when you look close to read.
When we prescribe a new pair of glasses, you need two sets of numbers written as distance PD and near PD, while it is often leaved out. Generally speaking, ordering glasses need them because it tends to custom-fit your glasses lenses to focus directly over your pupils, then your can feel better and have a clear vision. 'Optical center', which is the most significant point on the lens to ensure its best performance and least distortion in each spectacle lens. However, If the glasses pupillary distance for is not set correctly, there is no doubt that your eyes may have to strain to look through them, leading eyestrain headaches, visual distortion or even double vision. You can get your PD during a sight test in an eye office or retail location, which will cost you extra money for their service.