• Latest Med News

The Creation of Optical Illusions

By: Sai Srihaas Potu

Advances in the fields of molecular biology, developmental psychology, sociology, and cognitive psychology are catalyzing an important paradigm shift in our understanding of optical illusions. Visual illusions have fascinated psychologists for centuries, however, not many people have been able to understand the mechanisms behind the creation and implementation of illusions. Research in this field of psychology has been confined due to profound implications and the lack of unified judgments. In recent years, scientists have been able to develop a neuropsychological framework that illustrates how illusions are created and establish a better understanding of the phenomenon of perceptual constancy.

An optical illusion is when our brain perceives an image in a way that is different from reality. Cognitive illusions are good examples of proving how our expectations can influence our perceptions. Illusions can be experienced by anybody and these are not necessarily a symptom of some psychiatric issues like hallucinations, as hallucinations can take place in the absence of external stimuli. Illusions can be caused by cultural and psychological factors.

The phenomenon of perceptual constancy is expected to have taken place when one perceives the object as the same, despite the sensory changes. In the absence of perceptual constancy, there will be chaos and a lot of confusion around us, because the objects will appear to be different, whenever we look at them. Perceptual constancy can be explained as stability in our perception of the environment around us, even when the object is perceived in wide variations or circumstances. In the case of perceptual constancies, the brain processes information as a computer by taking into consideration all the possible parameters or cues for taking a decision pertaining to the probable size as well as to object distance.

In a recent study, researchers were able to discover that in some cases the things we see with our peripheral vision might be optical illusions. Our peripheral vision is outside the direct focus of our eye and sometimes our brain might fill in that peripheral view with illusions.

During the study, researchers presented 20 participants with a series of images. The participants were told to focus on the center of the screen while an image was starting to become visible in their periphery. The participants needed to click a mouse as soon as the difference between the central patch and the periphery disappeared and the entire screen appeared to be uniform. Subsequently, the researchers changed the physical characteristics of the central image, varying its shape, orientation, color, and shade.

The results showed that the majority of participants believed that the image they saw on the central screen was the same as the image that was visible through their peripheral vision. However, the images were not the same for any trial. Our brain has a strong connection with our central vision which allows it to properly understand and create an accurate representation of the perception. However, our brain’s connection with our peripheral vision is not the same. This study proves that the brain fills in what we see when the physical stimulus for our peripheral vision is not rich enough. The brain represents peripheral vision with less detail, and these representations degrade faster than central vision. Therefore, the peripheral vision is very susceptible to illusory visual experiences, for many stimuli and large parts of the visual field.

As we go about daily life, we generally operate under the assumption that our perception of the world directly and accurately represents the outside world. But visual illusions of various kinds show us that this isn’t always the case. As the brain processes incoming information about an external stimulus, we come to learn, it creates a representation of the outside world that can diverge from reality in noticeable ways.

Psychologists have analyzed the different mechanisms behind optical illusion for over a century. To this day, many people believe that illusions are fun to experience, but perception scientists create illusions in order to have a better understanding of the complexity of our brain. There are many things we don’t know about our brains. By understanding a perceptual system, scientists will be able to better analyze the variables that increase or diminish the strength of illusions. With further research being conducted, scientists will be able to understand the psychology behind optical illusions which will help them develop new techniques that will prevent neurocognitive impairment.


1. Eagleman D. M. Visual illusions and neurobiology. Nature Reviews Neuroscience. 2001.

2. Gandhi T., Kalia A., Ganesh S. & Sinha P. Immediate susceptibility to visual illusions after sight onset. Current Biology. 2009.

3. Marte Otten, Yair Pinto, Chris L. E. Paffen, Anil K. Seth. The Uniformity Illusion: Central Stimuli Can Determine Peripheral Perception. Psychological Science. 2016.

4. Segall M. H., Campbell D. T. & Herskovits M. J. The influence of culture on visual perception. Psychological Science. 2002.


© 2019 by Latest Med News