Try this illusion on for size:

marilyn

If you see a certain father of the bomb, you're okay. If instead you see a certain mid-century bombshell, it may be time to visit your optometrist. The Independent explains further:

As with the blue dress/white dress fiasco, we find Einstein easy to spot, but Marilyn comes though loud and clear if we either squint at the picture, or view a much smaller thumbnail version. Who do you see?