never contact with acid

Lens height about 1 5/8 inches (42mm)

Bridge (DBL) about 11/16 inch (18mm)

Lens height about 11/8 inches (28mm)

the clip-on attaches securely and stays aligned during everyday use

4 Pack Cat-eye Design Bifocal Sunglasses SBR2113 Fully Magnified Blue Light Readers never contact with acidPlastic frame with spring hinges Frame width about 5 1 2 inches (140mm) Lens width about 1 15 16 inches (49mm) Lens height about 1 1 2 inches (38mm) Bridge(DBL) about 1 2 inches (13mm) Temple length about 5 3 8 inches (137mm) EYEKEEPER BIFOCAL SUNGLASSES A crescent shape on the bottom part of the lenses have magnification, which is for reading and close up work. And the other parts of the lenses have no magnification,which is for distance viewing.