Knowing your specifications.
The most important part of buying eyewear online is knowing your specifications: your eye size, your bridge size, and your temple length. If you do not yet have prescription frames, we strongly recommend you have an optician take these measurements for you. If you do already have frames, these measurements are most likely engraved in them, and you should find them somewhere on the temples or the fronts.
For eye size, look for a number between 35 and 65.
For bridge width, look for a number between 14 and 24.
For temple length, look for a number between 130 and 170.
It is also important to have an idea of what type of frame is likeliest to suit you. If you've already found your own style, that's great! But in case you're unsure, here are a few general tips:
Round faces work well with rectangular frames.
Oval faces work with most frames.
Triangular faces work well with rectangular frames.
Square faces work well with oval or round frames.
Rectangular faces work well with oval or round frames with typically larger sizes.