Abstract: A transmittance-adjustable window (20) that includes first and second polarizer sheets (34B)(46B) and an actuator (44) for relative movement between them. The first sheet (34B) has a translation direction Y and is formed from an alternating series of abutting, identically-shaped linear polarizer segments A and B distributed along translation direction Y. Each segment A has a first polarizing direction and each segment B has a second polarizing direction orthogonal to the first. The second sheet (46B) is substantially identical to the first sheet (34B) and positioned in an adjacent, substantially parallel plane. The actuator (44) moves one of the sheets with respect to the other between an OPEN alignment position and an OPAQUE alignment position. In the OPEN position, each segment of the first sheet superimposes a corresponding identical segment of the second sheet which allows light to pass.