The common theme of all the figurative senses is of a gap not in visual function but in the mind's perception, cognition, or world view.

Common causes of scotomas include demyelinating disease such as multiple sclerosis (retrobulbar neuritis), damage to nerve fiber layer in the retina (seen as cotton wool spots[3]) due to hypertension, toxic substances such as methyl alcohol, ethambutol and quinine, nutritional deficiencies, vascular blockages either in the retina or in the optic nerve, stroke or other brain injury, and macular degeneration, often associated with aging.

[4] Less common, but important because they are sometimes reversible or curable by surgery, are scotomata due to tumors such as those arising from the pituitary gland, which may compress the optic nerve or interfere with its blood supply.

Beyond its literal sense concerning the visual system, the term scotoma is also used metaphorically in several fields, including neurology, neuropsychology, psychology, philosophy, and politics.

The common theme of all the figurative senses is of a gap not in visual function but in the mind's perception, cognition, or world view.

Even for people who intellectually understood that the leg or hand was supposed to be theirs simply could not believe it emotionally and could not completely reconcile reality with schema, prompting great unease.

And at the highest abstraction level are what have been called intellectual scotomas, in which a person cannot perceive distortions in their world view that are obvious to others.

Thus, in philosophy or politics, a person's thoughts or beliefs might be shaped by an inability to appreciate aspects of social interaction or institutional structure.