This is a quick tutorial on how to make your own illusion. This specific illusion is called the "Hermann Grid Illusion". For the full effect of the version I made, click on the image so it is full sized.
Step 1: Go to Paint, and Fill the Whole Screen Black
Use the paint bucket, and select the black color. Then, fill the whole screen with black.
Step 2: Draw a Few White Vertical Lines
The number of vertical lines should usually be more than three for a good effect. To draw the vertical lines, press the "line" shape button, and choose the white color. The end result should look like the photo shown.
Step 3: Add the Horizontal Lines
As said before, more than three lines is highly recommended for a good effect. Use the same line tool.
Step 4: Add the "junction Circles"
Now, add the small white circles at the junctions which the lines cross. To do this, select the draw oval tool, then make sure that the fill- solid color is selected. Next, simply put the circles in! The final result is shown in this photo.
NOTE: This is probably the most important step, as the circles do contribute to the effect ALOT.
Step 5: Enjoy!
I hope to see more instructables based on psychology and illusions on this site, as there aren't many compared to other subjects!
Anyways, enjoy your newly-made illusion!