field of regard vs visual field

field of regard and visual field both are nouns.

Word	Noun	Adjective	Verb	Adverb
field of regard	Yes	No	No	No
visual field	Yes	No	No	No

As nouns, field of regard and visual field are synonyms defined as:

field of regard and visual field: all of the points of the physical environment that can be perceived by a stable eye at a given moment

Other synonyms of field of regard include field of vision.

field of regard (noun)	visual field (noun)
all of the points of the physical environment that can be perceived by a stable eye at a given moment	all of the points of the physical environment that can be perceived by a stable eye at a given moment