The size shown on all products in our catalog is the horizontal extent or width, in millimeters, of each of the lenses, as seen in the following scheme (for "lens").

There is no right size is a matter of personal taste. Everyone has their preferences and style of their glasses as they should be or feel comfortable with them. In addition, many models are manufactured in only one size (UNIQUE). Having said that, we present the criteria used in the standard choice.
In OnlyLens we recommend the choice of the medium size, that is closest to the height 57.5 mm, taking into account the normal lens widths are between 45mm and 70mm. But it depends on your face dimensions and shape and of course on your personal preferences.
There are two factors involved in choosing the size of a sunglasses:
- Shape of face
- Head size
Therefore, for a face or head size more appropriate one size larger and a smaller size stylized faces.
Below are the different types of face preferences to choose size and shape of the suggestion of lenses:
Oval: any size and shape.
Round: size medium / large and broad with angular shapes or rectangular styles.
Diamond: size medium / small. Forms oval, square or rimless.
Square: large sizes. Ways in oval, round or cat eyes.
Rectangular: size medium / small. Round or square shape
Triangular: medium sizes. Forms a thin top line or cat's eyes.