Smart glasses, particularly popular models like the Ray-Ban Meta, typically come in two main sizes—Standard (approx. 130mm–133mm hinge-to-hinge) and Large (137mm+ hinge-to-hinge)—designed to fit various face widths, ranging from 130mm to over 140mm. Proper fit is determined by eye size (lens width), bridge size (nose gap), and temple length (arm length), commonly measured in millimeters.

• Standard (e.g., 50 eye size): Fits average faces, with a hinge-to-hinge width of about 130mm.
• Large (e.g., 53 eye size): Suitable for larger heads, with a hinge-to-hinge width of 137mm.
• Measurement Tip: According to, those with a face width over 140mm should choose the large size to avoid discomfort.