Abstract: A low drag passenger-cabin window for use on an aircraft fuselage having a generally cylindrical shape, in which the as-manufactured geometry of the window is modified so that the shape of the window at cruise altitudes is aerodynamically optimized. The window comprises a pane of transparent material. The inner and outer surfaces of the peripheral portion of the pane as manufactured conform to a generally cylindrical shape, while the inner and outer surfaces of the medial portion of the pane as manufactured are depressed inwardly in a prescribed manner relative to the peripheral portion. The surfaces of the medial portion are adapted to deflect outwardly to conform to a generally cylindrical shape in response to a predetermined air pressure differential and/or a predetermined temperature gradient experienced at cruise altitude.