One of the most important tools used by neuroscientists to understand how the brain creates its sense of reality is the visual illusion. Because of this disconnect between perception and reality, visual illusions demonstrate the ways in which the brain can fail to re-create the physical world.

Optical illusions are cleverly designed to distort reality, but did you know that the same distortions occur frequently in everyday life? Our ability to see involves the brain moulding raw sensory data into a refined form. Some of the refinements are deliberate – they’re designed to help us survive.

Although illusions are by definition not real, scientists are increasingly finding ways to use them to make an impact on the real world. Here are 10 practical applications that use or control illusions, from warships to virtual reality to Michelangelo’s David and the Statue of Liberty. All MP3s are based on illusion.

The psychological concept of illusion is defined as a process involving an interaction of logical and empirical considerations. Common usage suggests that an illusion is a discrepancy between one’s awareness and some stimulus.

An accelerated path. Optical illusions work because your brain needs a little rest, so it devised a few shortcuts along the way. Things like colors, shadows and perspectives help the brain understand what it’s seeing, so your brain starts to form an opinion based on these clues.

Optical illusions happen when our brain and eyes try to speak to each other in simple language but the interpretation gets a bit mixed-up. For example, it thinks our eyes told it something is moving but that’s not what the eyes meant to say to the brain.

A cognitive illusion is a common thinking error or thinking trap. Cognitive illusions are endemic in the normal population, where they’re usually asymptomatic.

Cognitive illusions are commonly divided into ambiguous illusions, distorting illusions, paradox illusions, or fiction illusions. A striking example is the Café wall illusion. Other examples are the famous Müller-Lyer illusion and Ponzo illusion.

A cognitive bias is a systematic error in thinking that occurs when people are processing and interpreting information in the world around them and affects the decisions and judgments that they make. Biases often work as rules of thumb that help you make sense of the world and reach decisions with relative speed.

Ambiguous images or reversible figures are visual forms which create ambiguity by exploiting graphical similarities and other properties of visual system interpretation between two or more distinct image forms.

An afterimage or ghost image is a visual illusion that refers to an image continuing to appear in one’s vision after the exposure to the original image has ceased. These are images that can form two separate pictures.

Lenticular printing is a technology in which lenticular lenses (a technology that is also used for 3D displays) are used to produce printed images with an illusion of depth, or the ability to change or move as the image is viewed from different angles.

An autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image. A hidden 3D scene emerges when the image is viewed with the correct convergence.

Try them on the simple stereogram below. Viewing Techniques: Most Stereogram pictures are usually generated so that if you look at (converge your eyes on) a position twice as far away as the picture, and focus on the picture, generally after a few minutes you see a surprising 3D image!

Double vision occurs when a person sees a double image where there should only be one. The two images can be side by side, on top of one another, or both. The condition can affect balance, movement, and reading ability. If double vision affects just one eye, it is monocular.

Humans have two eyes, but we only see one image. We use our eyes in synergy (together) to gather information about our surroundings. They show each eye a slightly different image. The two images show the objects as seen from slightly different angles, as would be when you saw the object in real life.