text:  When you're in the dark, of course, your pupil opens right up. People who have imagery, if you ask them to imagine, say, looking at the sun. Your pupil actually constricts. As if they were actually looking at the sun. But if someone with no images in their head does this. You don't get these effects. Not at all. Not at all. Yeah. Yeah. Wow. And there's even a name for this, for not being able to see in your head. Aphantasia.