Things You'll Need
Instructions
Seek out reference books and online resources that provide photos of popular eyeglass frame styles from the past. Familiarize yourself with styles and materials, as well as eyeglass frame manufacturers and marks.
Gently clean the frames by rubbing them with a soft, dry polishing cloth. This will often reveal markings which have been obscured by years of dirt.
Using a flashlight and magnifying glass, look carefully for any markings, which are typically located on the inside of the temple pieces, but may be found anywhere on the inside of the frame. According to the "Guide to Vintage Eyeglass Makers Marks & Companies," marks can include the temple length, a maker's mark, the country of origin and gold content for wire frames. If the frames are unmarked or if the marks are faded, the eyeglasses can be dated by determining the style and material.
Identify the material of the frames. Are they wire rims or tortoise shell, or are they made from popular early- to mid-20th century materials such as celluloid, Bakelite or early plastic? Familiarize yourself with these different materials by referring to reference books and Internet sources.
Look at the style of the eyeglass frames. Are they round, with long, wrap-around temple pieces (popular in the 1800s), "cat's eye" style, with slanted tips, or square-shaped? Refer to reference materials to identify the popular shapes and styles of different eras.