field of view vs visual image

field of view and visual image both are nouns.

Word	Noun	Adjective	Verb	Adverb
field of view	Yes	No	No	No
visual image	Yes	No	No	No

As nouns, visual image is a hypernym of field of view; that is, visual image is a word with a broader meaning than field of view:

field of view: the area that is visible (as through an optical instrument)
visual image: a percept that arises from the eyes; an image in the visual system

Other hypernyms of field of view include visual percept.

field of view (noun)	visual image (noun)
the area that is visible (as through an optical instrument)	a percept that arises from the eyes; an image in the visual system
	a mental image that is similar to a visual perception