Apparat zur Feststellung der Dioptrien des Augen (Dioptrimeter)

Help find the history of the device. There are 2 controls, a rotating wheel, large and small.

 

It's from an optometrist's office for sure and looks like one used for fitting lenses for eyeglasses. A lot of the good optical equipment came from Germany before WWII, and afterward too. The box looks post-War. Alternately, dioptremeters are used for precision optics. https://www.seilerprecision.com/products/dioptometer/

 

One wheel for + or - diopter, and one wheel for astigmatic correction.

 

No wonder it's familiar! Wheel hard over, matey!