An electronic confidential document viewing method is performed by an electronic device in electronic communication with a pair of eyeglasses. In response to display a confidential document on a display device, a protection image is generated based on a security image of the confidential document. The protection image is a copy of the security image that is offset from the security image by a predetermined distance in a vertical direction or a horizontal direction. The security image and the protection image are synchronously transmitted to the display device. The display device displays an overlapping picture based on the two images. The eyeglasses receive the overlapping picture, and separate the overlapping picture into two images. One of the two images is viewable by the left eye of a viewer, and another image is viewable by the right eye of the viewer.