This study examines control options for a daylight dimming system in an open-planned office to maintain required lighting environments with effective lighting energy savings and acceptable glare ratings. Computer simulations were performed for photosensors with three ranges of viewing angles in two daylit perimeter zones of the office, followed by consecutive computational processes. Three CIE standard sky and blind conditions were employed to predict indoor daylight illuminance, photosensor illuminance, and daylight glare probability (DGP).The results imply that the glare can be imperceptible and the daylight dimming control system effectively applied, since 90.74% and 86.67% of total cases in the east and south-facing zone respectively generated daily mean DGP values lower than 0.35. Under clear sky, the horizontal and 45 degree blind combined with full or partial shielding in the south-facing zone achieved successful dimming controls with lighting energy savings of up to 87.5%. For the east-facing zone under clear sky, the viewing angle range of photosensor should be narrowed using full shielding to achieve effective control performance with lighting energy savings of up to 62.6%. Under overcast sky, effective control performance was rarely achieved due to the lack of daylight and a daylight dimming system was not necessarily required.