We should always pick the right sunglasses to fit our facial structures. The rule of thumb is if you have a wide face it is best to wear wide sunglasses. The only way to determine if you have a wide face or not is by taking a measuring tape and measure it yourself. Measure across your face from side to side and you will be able to see which type of faces you have. Anything under 127 mm is considered narrow, whereas anything over 140 mm is wide and in between the two ranges is medium. It is best to buy sunglasses that fall under the same spectrum of your face shape.