Do you have...

[TrekStar]

Wasn't that a Disney movie back in 1940 or something?

[Brazoo]

Almost correct, except for the "voluntarily" part. It simply cannot visualize.

The Wikipedia article footnotes an article by Professor Adam Zeman published in 2015 called "Lives Without Imagery - Congenital Aphantasia" which claims:

"...it was identified that aphantasia characterizes only voluntary visualizations; the aphantasiacs were still able to have involuntary visualizations (i.e. dreams)."

[Brazoo]

Follow up - just visited a forum discussion with aphantasiacs explaining that they see vivid images when they dream. Some of them claim they don't. So, it's just that simple and fascinating.

Here's a quote from one of them:

"Yes. When I dream I do see vivid images, but I didn't know other people are able to do so when they are awake until I heard of the term aphantasia."

Link to the forum:

https://www.quora.com/Can-people-with-aphantasia-dream