Glasses can be marked or found by their primary function, but also appear in combinations such as prescription sunglasses or safety glasses with enhanced magnification.
Corrective l… See more

The ophthalmic frame is the part of a pair of glasses that is designed to hold the lenses in the proper position. Ophthalmic frames come in a variety of styles, sizes, materials, shapes, and colors.
• pair … See more

Corrective lenses can be produced in many different shapes from a circular lens called a lens blank. Lens blanks are cut to fit the shape of the frame that will hold them. Frame styles vary and fashion trends change ove… See more

Scattered evidence exists for use of visual aid devices in Greek and Roman times, most prominently the use of an emerald by Emperor Nero as mentioned by Pliny the Elder.
The use of a … See more

The market for spectacles has been characterized as having highly inelastic demand. Advertising restrictions in the United States, for example, have correlated with higher prices, suggesting that adverts make the s… See more