Relating to or denoting mental images having unusual vividness and detail, as if actually visible. Though based on the Ancient Greek “εἰδητικός” (meaning “constituting an appearance”), the word was only coined in the early 1900s by German psychologist Erich Rudolf Jaensch who used the term “eidetisch” to describe the particular precision of mental images that were different from and far clearer than regular memories.
“Eidetic” is often used interchangeably with “photographic” to describe the capacity for incredibly detailed and precise memories, but there is a difference between the two terms. Photographic memory usually describes the ability to recall detailed information (including texts and numbers), while “eidetic memory” describes an ability to maintain a vivid picture of something after it is gone, even experiencing a feeling of the image still being present.
Example: Memories of my recently-departed friend have been occurring with eidetic clarity.