This is an antique trial lens kit made by the American Optical Company.  It comes with everything needed for an early travelling optometrist or optician at the turn of last century.  The exterior, once covered with leather, is quite worn...but you'll find a gem of an optical antique once you open it.  There are two sections, each under by a protective hard cover. One half contains a tray of eyeglass lenses ready to be inserted into frames.  Underneath that tray is a hidden compartment with a foldable eye chart.  The other half includes a complete tray of antique trial lenses.  None are missing - all powers are in their correct slots.  Under this tray are a set of trial frames as well as an antique eye chart.  With its historical significance and unique design, this will be a valuable addition to any antique collection related to the field of optics or eye care.