Term coined in 2015 by a research team led by British neurologist Adam Zeman for an invisible congenital disability, whereby a person is unable to voluntarily form mental images.

NOTE: This condition was also described in 1880 by Francis Galton, a British statistician and polymath, but had otherwise received very little attention, until recently. Many people who are unable to visualize are only vaguely aware, and sometimes completely unaware, that being able to see in one’s ‘mind’s eye’ is not simply a metaphor but something most people can actually do without effort. Zeman became particularly interested in studying the congenital condition when, after publishing a paper about a man who had lost the ability to visualize following an operation, he began receiving messages from people who explained that they never had been able to mentally form visual images.

Reference: http://www.eugencpopa.ro/wp-content/uploads/Afantazia-.pdf