visual defect vs vision defect

visual defect and vision defect both are nouns.

Word	Noun	Adjective	Verb	Adverb
visual defect	Yes	No	No	No
vision defect	Yes	No	No	No

As nouns, visual defect and vision defect are synonyms defined as:

Other synonyms of visual defect include visual disorder, visual impairment.

visual defect (noun)	vision defect (noun)
impairment of the sense of sight	impairment of the sense of sight