These unique eyeglasses / spectacles were popular during the late 1700's and early 1800's. They are not sunglasses by today's standards. In 1750 James Ayscough began making these double hinged spectacles with tinted lenses to be worn as regular eyeglasses. He felt that the tinted lenses would remove the glaring light better than clear lenses. The spectacle arms are pivoted at the temple and can rotate 360 degrees and fold inwards. The double lenses fold out towards the sides to give further protections to the eyes. From hinge to hinge in the front they measure 4" across. Both sets of lenses measure 1 1/4" X 1". The sidebars measure 7" when fully extended. The metal looks to be steel and is a little rusted in places. The lenses have the usual scratches from wear.