When PRELOAD IMAGE is enabled, Stereoscope Applet loads the next image in the background, while you can look to the current image! When the next image is completely loaded, the mouse changes to a hand cursor. After clicking, the next image will be displayed!
When SWAP L/R is enabled, the left and right image is swapped. Use this option only, when you can't see a stereo effect. Normally the webmaster should be responsible for correct left/right order!