To do parallel-viewing, you must aim your eyes through the image and into the distance. The problem is there's a solid object in the way -- a computer monitor or a book or something! How do you look through a solid object?! Well, generally, we look directly at what we want to see and leave the X-ray vision to Superman. In this case, we've got to develop our own superpowers.

Look as closely as you can at the image and then very slowly-move the image away from your face until the hidden 3D object takes shape and is recognized.
This technique can be adapted to learn to see stereograms on a computer screen.

1. Since you can not pick up the computer monitor and move it away from your face, try moving your body away from the computer screen. Get up out of the chair and onto your feet. Prepare to assume a slightly contorted position.

2. Put your nose right up against the computer screen. The image will become very blurry. Admire those glowing blotches of colour. The point is you have just easily defeated your tendency to focus right at the surface of the computer screen. In order to see the 3D image you must look through the computer screen, not at the computer screen.

3. Now move your face back from the computer screen while maintaining the same position of your eyes. Allow the image to remain blurry

4. The hidden 3D image will gradually come into view.

5. Continue aiming your eyes beyond the computer screen. Do not look directly at the image or the computer. If you suddenly shift your focus and look right at the screen, you will lose the 3D effect.

6. Once you recognize the 3D shape, if you continue to look into the background rather than directly at the shape, the 3D effect will increase. Stereoscopic perception seems to have a saturation effect in the brain, so if you keep looking at the image for a while you will notice that your perception of the depth increases... Now have a look at the images and see how you get on.