Antique Cased Brass Ophthalmic Instrument with Twin Adjustable Needle Points, 19th Century Optical Tool

A precision brass instrument of unusual form, fitted in its original red morocco case. Two lozenge-shaped brass carriers ride on a slotted frame, each locked by its own knurled thumbscrew, and each carries a fine steel needle point at either end so that the opposed points can be set to a precise separation and held there. The whole thing is tiny, beautifully made, and adjustable to a hair.

The instrument comes from the eye trade. Instruments of this pattern were used at the optician's bench for setting and marking the optical centres on a pair of spectacle lenses, and for the fine measuring work that went with fitting and glazing frames, where a repeatable separation between two scribed points was what mattered. The fitted case is of the kind supplied with ophthalmic and optical bench instruments rather than with surgical sets.

Sold as a cased antique instrument. We have not been able to tie it to a particular maker or catalogue number, and we would be glad to hear from a buyer who can place it exactly.