Yes, it is true that Pearl is a fifteenth-century elegy containing a dream vision. A dream vision is also known as visio. If you are a literature enthusiast, you are familiar with it for sure. It is a literature device used by some authors. By the word itself, dream vision means having the dream or vision which is only available through dreams or when a dreamer is sleeping. In case that the dreamer wakes up, the dream or vision will no longer be revealed to the dreamer. The Pearl is a poem but the author is still unknown.