your present prescription. I keep mine in the health file in my own filing cabinet. If you cannot find your prescription, visit wherever you earlier had your eye examined and demand a duplicate. Your optician, optometrist, or ophthalmologist is required by law to release your eyewear prescription to you. You now need to make note of a few critical bits of information from your prescription (see example above–click to enlarge). Among other information, you should see three columns on your prescription–sphere, cylinder, and axis.
Within the example prescription above, you'll see the Pupillary Distance of the patient is 62. Write down this number also, it's the seventh of your seven critical figures.
A relatively less critical quantity is your temple span. If you're lucky, you'll also visit a temple period and bridge size in your prescription. If not, don't perspire it, you can determine it out yourself. The temple duration describes the length of the two bars that connect the glasses to your ears. It is measured from where in fact the 90-degree curve from your zoom lens structure to the side bars (temples) starts to the very end of the temple, including the curve. It isn't measured from the flex point of the temples, because the "stub" between your flex point and zoom lens structure is not really a standard size.
Now, remove some measuring tape (ideally the type of tape used for fitting clothes and sewing, as it is very flexible) and evaluate an existing couple of glasses that fit perfectly. The average temple size for men is 135mm or 145mm. For ladies, 130mm to 140mm is standard. If the tape only has in ., measure to the nearest eighth or sixteenth and multiply that number by 25.4 to have the dimension in millimeters. Temple lengths are generally available in 5mm increments, such as 130, 135, 140, 145, etc. At most online glasses stores, temple length is shown within the frame description which is not customizable. Therefore, you need to discover a frame with a proper temple size. This occasionally varies if you are at a site specializing in designer glasses, where you have the choice to source your own temple size.
Seriously, temple size is not really a huge deal. I have one pair of spectacles with 135mm temples and another with 140mm temples. Both pairs fit comfortably. If for some reason you can't think of a temple measurement, don't let that stop you from making an eyewear purchase online. Instead, simply choose 140mm temples if you are a man and 135mm temples if you are a female. It's likely that, this length will fit pleasantly.