A display apparatus having a pair of polarizers with an optical rotator therebetween, one of the polarizers being a variable polarizer which is independently operated to alternate between substantially orthogonal states of polarization and cause the display to rapidly alternate between a normal positive and inverted negative image, creating a combined neutral image that in indecipherable to the naked eye. Shutter eyewear synchronized with the variable polarizer is used to extract the positive image for viewing by an intended viewer. In another embodiment, both polarizers of the display apparatus are independently variable, which allows for viewing of the desired image using passive polarized eyewear or eyewear incorporating synchronized variable polarizing rotators. Faster independent operation of the variable polarizers provide for flicker-free viewing of the desired image and convenient switching between normal and secure modes of operation, without physical alteration of the display.