A classic optical illusion created many years ago by neuroscientists at the Massachusetts Institute of technology helps you test your eyesight and find out if there’s anything wrong with your vision.

As the image gets larger, most people see a somewhat blurred image of German theoretical physicist Albert Einstein. If you are one of those people, we have good news for you: your vision is right as rain.

However, if you only see a certain legendary Hollywood star by the name of Marilyn Monroe when the image gets larger, you may need to visit your optician. Why? It all has to do with our eyes’ ability to pick up contrast and details as explained in the video below. Which one do you see?