Buying eyeglasses online exactly can save you more time and energy on the condition that you have chosen the right sized one. A glass model is of one particular size and numerous eyeglasses can be made in the same size. In general, when considering the size of eyeglasses you will have to take into consideration four basic measurements: the eye, bridge, temple and the vertical height of the eyeglasses. So you can decide your eyeglass size by measuring the four factors of your own. At last you will have to get your total eyeglasses width, i.e. how big your eyeglasses frame is, which is determined by your face shape. As long as you have got a exact measurement of all the above-mentioned factors you will choose the right sized eyeglasses.