Press Eyeball or click large black image.
This will have the program create a cluster of images. The program will start with two or three images in the cluster. It will be shown on screen for a limited time.

Wait for image to go black.
If will take about two and one half seconds for the image to go away. Use this time to study the image in preparation for the next step.

Press image icons on right.
After the image disappears look for and click on the icons to right which were in the cluster just displayed.

If you are right you will hear a ka-ching sound and the program will wait for you to select another image found in the cluster. If you click a wrong image you will hear a thunk and that's all she wrote. The cluster is displayed for you edification and one red point is added to the center bar.

If you successfully click on all of the images used in the cluster you will hear a Zwoooeee sound, the image will be displayed for your edification and a green point is added to the top indicator bar.

Lather, Rinse, Repeat.
Keep getting clusters right and you will go up a level.
Keep getting clusters wrong and you will be sent back to a previous level so that you can gain some practice under somewhat less challenging circumstances.