Step 1
Open up a new file. Size 300×300 in pixels. Click the paint brush or click B and use one of the default round brushes. Set the size as 15. Don’t worry about the other settings.

Step 2
Now take your brush and scribble random lines everywhere but leave some white space too. [screen shot]

Step 3
Now go to Effects>>Distortion Effects>>Pixelate. [screen shot]

Set the block width and height to 20 pixels. And make sure to have Symmetric checked. [screen shot]

Step 4
Now go to Effects>>Geometric Effects>>Circle. [screen shot] and set your settings as mine. [screen shot]

Step 5
Now you can take the background eraser and erase away the background part that is black or you can leave it there.