This interesting piece of eye wear is a pair of Vintage Keeler 420/2.5X Magnification Spectacle Magnifiers / Loupes.
They are in pretty good used condition and are sold without a box or intructions. They were made by Keeler in the UK: a premier manufacturer of optical visual aids for the medical professional.
Comprising a pair of Spectacles with planar (plain glass) lenses with a loupe attached to the bridge part of the glasses. The loupe can be lifted clear of the glasses, and the two eye pieces moved sideways to optimise vision depending on the width of the bridge of your nose.
They were bought for my visually impaired mother-in-law to enable her to read the newspaper without having to use a handheld magnifier. They work fine but she found then too heavy for the bridge of her nose and only wore them twice!
Being 2.5x magnification, at an optimum distance of 420 mm, these little magnifiers offer hands-free viewing with a nice bright image.
