<human>: Throwaway. Also posted on /r/relationships, but it wasn't terribly helpful.

I was showing my boyfriend a pinterest board of mine and trying to help him understand that I need encouragement, and I said something like, "you could tell me how pretty something is," and he told me that he doesn't know how to quantify "pretty." I asked him if that meant he found nothing pretty and he said that was correct. And so that I wasn't misunderstanding, I asked him if that meant I was not pretty to him. I can't remember his exact words but it was essentially, that's accurate. I asked him if any woman was pretty to him, and he said no, that he doesn't know how to measure something like that. That's just not how his mind works. I'm okay now with him not finding me pretty, as long as no other woman is pretty to him. I'm certain he's heterosexual. He says that he is attracted to me and that I am attractive and he finds me beautiful, but he's more attracted to personality than looks, though looks are a part of what attracts him. I've spoken with a friend about this and he said he's heard about that being a thing. Not being able to "see" beauty & prettiness. I'm sorry if I'm not explaining this very well, I was hoping reddit could help. This is the first I've heard of anyone being this way.

Summarize the given text in a few sentences.
<bot>: Boyfriend can't "see" beauty or prettiness and I am having trouble finding out out if this is a thing.