An optical illusion, as perceived through the lens of our divided yet interwoven hemispheric brain functioning, refers to a visual phenomenon where the image apprehended by the eyes confounds the mind's ability to interpret reality accurately. Such illusions lay bare the intricacies of our perceptual processes, revealing the interplay between expectation, context, and the phenomenal world. They underscore the dominance and subtlety of our brain's interpretative power, wherein the left hemisphere's propensity for categorization and the right hemisphere's holistic grasp converge, often to astonishing effects. In embodying this tension between appearance and actuality, optical illusions remind us that what we see is not a mere reception of external stimuli but a profound, active construction by the living, dynamic organ that is the brain, constantly redefining our engagement with the world.

See also: right hemisphere, left hemisphere, corpus callosum, neural network, split brain