The invention comprises improvements to transparent/translucent panel systems including two spaced flat panels and a series of elongated, abutting, rotatably mounted transparent/translucent light-controlling members disposed between the panels in which the light-controlling members are at least partially tubular or have annular members along their length to facilitate rotation of the light-controlling members and include a light-blocking surface including improvements to ensure continued efficient operation when the panel systems are subjected to flexure or deflection and possible permanent deformation.