A Brewster-style stereoscope is based on the first design by David Brewster in 1849. It is a compact hand-held stereoscope consisting of a closed box with two lenses. A door on top can be opened to illuminate paper card stereoviews or daguerreotypes via reflective light. The bottom usually contains a frosted glass which is intended for illuminating glass stereoviews via transmitted light. Brewster-style stereoscopes were popular until the 1930s.