Upside Down - Optical Illusion Camera app for iPhone and iPad

**FREE FOR A LIMITED TIME!**
With this app you can easily create and share upside-down face illusions. The illusions can be generated from:

- Photos taken with the built-in camera
- Portraits found on the internet with the built-in “Face Search Engine”
- Images from the Photo Library of the device.

How does it work?

The upside-down portraits generated by this app looks perfectly normal at first glance. However, when you rotate the photo the right way up the face will appear funny, strange or even grotesque. This effect is due to the eyes and mouth being inverted.

But why dont you spot this when the photo is upside down?

There are specific parts of your brain dedicated to face perception. However, because you rarely look at upside-down faces, these parts of your brain works best with upright faces. Your brain processes visual input in pieces before it makes a whole image. When presented with an upside-down face, your brain is able to identify the individual parts, such as the eyes, nose and mouth, but have a hard time perceiving the relationship between these parts and the face as a whole; hence it doesnt discover the distorted face - despite the changes being obvious in the upright face.

This phenomenon is also called the “Thatcher effect” or “Thatcher illusion” and was originally discovered by Psychology Professor Peter Thompson in 1980. It was named after the former Prime Minister Margaret Thatcher on whose photograph the effect was first and most famously demonstrated.

And now we finally have an app that can do the trick.
Download it, try it out, flip your phone and have fun!