Abstract: The invention comprises a ventilator for a glass block window that includes a window frame, a window sash pivotably mounted in the window frame and a screen also pivotably mounted in the window frame. The window sash is pivotable between a closed position and an open position such that when the window sash is in the open position, rain and snow and the like are resisted from passing through the ventilator and into the building which has the glass block window. The invention also encompasses providing a ventilator as described above without the screen. Finally, a screen for a window is also provided. The screen is pivotably mounted to the window frame of the window. This screen can be used not only for the ventilator but also for other types of windows.