Finding the right frame size is easy. Use a credit card and follow the steps below.
Step 3 - Now check the position of the card
Understand your glasses measurements easily
Printed inside the frame (e.g. 51-21-145). The last number (145) is the temple length in mm.
First number (51) shows lens width. Measured horizontally across the lens.
Middle number (21) is bridge width. Distance between lenses on nose.