Aphantasia is when your brain doesn’t form or use mental images as part of your thinking or imagination. Experts don’t define aphantasia as a medical condition, disorder or disability. Instead, it’s a characteristic, much like which hand you naturally use to write. Available research indicates it’s simply a difference in how your mind works.

Imagination is how your brain “simulates” something based on knowledge or past experience. For most people, imagination can take many forms (things you can see, hear, taste, etc.). And some people have stronger imagination abilities than others.

Think of visual imagination like a television. Some people have black-and-white TVs. Others have color TVs. An extremely vivid imagination is like having an ultra-high-definition digital television.

Having aphantasia is like your mind not having a TV because it wouldn’t use it. Because your “mind’s eye” doesn’t work like that, your imagination works in other ways.

More Info: my.clevelandclinic.org