Historical information

Trial frames are used to hold trial spectacle lenses in front of the eyes to establish the spectacle refraction. This unit is able to hold 3 lenses in front of each eye. It is very complex for its early date.

Significance

This trial frame is a rare example of a very complex early design which has survived in good condition.

Physical description

Complex nineteenth century trial frame: double lens clip to front rotated by long control knob. Single downward pointing lens clip to back. Bridge height and extension adjustable. Variable inter-pupillary distance calibrated in inches. Slide extending curl sides.

Inscriptions & markings

Eye rims stamped:'PAT NOV.6.94 & PAT JUNE25.95'. Sides stamped:'PAT APR.30.95'