Optical illusions are manifold and often concern everyday things that we don’t think twice about. For instance, it appears to us that the sun rises in the east and sets in the west, traversing across the sky during the daytime. Yet, it is the Earth that is actually moving around the sun. Another common optical illusion is how mirrors in a room or attached to a car make objects appear larger or more distant than they actually are. The reason for this is based on how reflected light is perceived by our eyes. It is also the basic premise behind most fun houses, where distorted mirrors make us question the very reality of how we see ourselves.
The eye is one of human beings’ most intricate organs. The way we see is based on the light that falls on an object getting reflected to make an inverted image on the retina of the human eye. Light striking the retina commences a proliferation of chemical and electrical events that ultimately trigger nerve impulses in various visual centres of the brain through the fibres of the optic nerve. The brain then interprets the image transferred through the optic nerve and we perceive the object.
Optical illusions are a result of mistaken judgment about what our eyes process to our minds. Anatomically speaking, the eye is comprised of two types of nerve cells, namely, the rods and cones, which are patterned on and around the retina. The cone cells are responsible for detecting colour and the rod cells detect contrast. The two types of cells together convert light into neural messages or signals. Now, on the edges of the retina, there is a disparity of rods to cones, and in the center of the retina there are only cones. This relates to optical illusions because by seeing things from the corner of the eyes, such as we do with peripheral vision, images are often deceptive. This is why you’ll often hear people describe seeing ghosts or lurking images out of the corner of their eyes.
Moreover, for all of those pictorial illusions where we see movement at the center of a circular or spiral design, such as the famous “Isia Leviant’s Enigma,” excessive exposure to alternating patterns, tilt, brightness, or colour may affect our perceptions. For instance, excessive stimulation of specific regions of the brain can cause a cerebral imbalance, thus affecting how we perceive certain objects. Our eyes may also become tired by such overexposure, likewise causing us to see things differently.
Visual illusions, at their core, are basically defined as a dissociation between physical reality and subjective perception of an object or event. Whether we see something that is not actually there, or fail to see something that is, there is a mutual relationship at play between the retina, optic nerve, and cerebrum where, like some kids playing the game whisper down the lane, something often gets lost in transmission.
Of course, if you’re not seeing basic everyday things in your classroom, office, or household, look into your options for LASIK vision correction with the experts at LASIK MD.
Do you have a question about LASIK? Ask one of our experts!
Also available in/Également disponible en : French