I would strongly recommend against this product.  The thick lenses would seem to be made of solid glass.  They are impractical for almost any activity given how extraordinarily front heavy they are. Since buying these, friends have shown me their glasses, those being made of plastic, making them much more practical.  Also, the lenses could be clearer.  Much like most diffraction glasses, the product blurs vision in addition to distorting in the intended way.