When purchasing sunglasses or frames for prescription lenses online, it's very important to know that the glasses will fit your face properly before placing your order. There are four main measurements that you will need: frame width, frame length, bridge distance and pupil distance. Pupil distance is especially important when purchasing prescription glasses so lenses can be made correctly. Also, most retailers measure their glasses in centimetres. These measurements will be important when purchasing sunglasses online, so you know if the pair you want will fit you or not.
Measure the distance from the centre of your left pupil to your right pupil.
Measure the width of your nose closest to your eyes. This will be the bridge measurement and is important because you want the glasses to sit snugly on your face.
Measure the distance from the top of your ear to your eye. This is the sunglasses' length; it's best to measure a pair of glasses that you currently own that fit will.
Measure the distance from your left temple to your right temple. This will be the frame width measurement.