Retro eyewear

You know what you don't see much of nowadays?

The monocle.

You know, the single eye piece adorned by nineteenth century capitalists, German military officials, Karl Marx, The Penguin, and Colonel Mustard.

What an odd choice for a corrective lens, don't you think? Essentially, a rounded piece of glass is jammed into the eye orbit, and a string or light chain is used to connect the monocle to an item of the wearer's clothing, in the event that he or she tired of the constant squinting...