Depending on its location and severity, a TBI can affect your vision by damaging parts of the brain involved in visual processing and/or perception (e.g., cranial nerves, optic nerve tract or other circuitry involved in vision, occipital lobe).
Imagination, also called the faculty of imagining, is the ability to form new images and sensations in the mind that are not perceived through senses such as sight, hearing, or other senses.
The noun 'dream' is an abstract noun; a word for a series of thoughts, images, and sensations occurring in a person's mind during sleep; a word for involuntary ideas. An abstract noun is something that cannot be experienced by any of the five senses; they can't be seen, heard, touched, smelled or tasted.