Eye wanted to know this, and hopefully you did too! Bone spectacles, related to the 4th and 3rd millennia BC, were found during archaeological excavations in Yanik Tappeh by Dr Ali Akbar Sarfaraz in 1962 with the remains of the body of dead girl.
These spectacles were carefully studied by Mr. Mir Ghafar Sahihi Oskooei a researcher at the Shahid Beheshti University of medical science. They were proved to be medical spectacles due to his studies and the human needs for re-correcting eye problems in the 3rd Millennium as well as for the techniques used in their production… The spectacles were originally made of the bone of a domestic herbivorous mammal. (Wikipedia source)
The Eskimos made Sun Glasses from wood, leather and whalebone
One of the rarest bones to be made into eyeglasses was Whalebone or Baleen. Used from the late 17th to the early 19th century.
Circa 1800′s Bone Opera Glasses
While real bone, buffalo horn eyewear is limited and expensive, there are several alternatives:
Linda Farrow x Jeremy Scott Bone Eyewear- Acetate with a Fred Flinstone Flair
And a Skeleton Look by Shouichi Tomita on Facebook a Japanese designer/blogger and eyewear Fashionista.