Choosing the right frame size for your face is as well important as the lens or the glasses. Knowing the measurements of your frame will help you to select the best glasses. Thankfully, it's easy to find your frame size on your current pair of frames.
Sunglasses tend to be larger than eyeglasses, so your sunglasses size will most likely be different than your eyeglasses size. With sunglasses, you have more freedom to choose within a wider range of sizes, since the fit does not need to be as precise.
Every pair of glasses is a little different, so the size information may not always be located in the same place.
Look on the inside of your current frames. You will find the size information stamped either on the temple, like this example:
Or on the bridge, like on this metal example:
or like on this plastic nose bridge:
On some models, you may also find the size stamped on the earpiece.
THE LENS HEIGHT
The length height is the vertical height of the lens. The measurement of the lens should be done vertically, at its tallest point. The lens height should be at least 26 mm.
THE LENS WIDTH
The length-width is the horizontal diameter of one lens. Doctors may refer to this as “eye size.”
Measure the lens horizontally, at its widest point. Make sure the lens width accommodates your pupillary distance so that your eyes align with the “optical center” of the lens. Measure your PD using this guide. Your lens width should be at least 54 mm.
The bridge is the part that goes across the (bridge) of your nose—hence the name.
The bridge should be measured horizontally, at the top of the bridge, from the edge of one lens to the other. The bridge measurement should be 20 mm.
The temple connects to the front of the frame on both sides and extends behind the ears.
Measure from the hinge—where the arm connects in the front— to the spot where the arm begins to bend down around the ear. Then measure from the top of the bend to the bottom tip. Add the two sections together for the total temple arm length. The temple size should be at least 134 mm.
The frame as well is measured horizontally across the entire front of the frame. Include any lug or hinge pieces that stick out on the sides. The size of the frame should at least be at least 136 mm.