dullness vs visual property

dullness and visual property both are nouns.

Word	Noun	Adjective	Verb	Adverb
dullness	Yes	No	No	No
visual property	Yes	No	No	No

As nouns, visual property is a hypernym of dullness; that is, visual property is a word with a broader meaning than dullness:

dullness (noun)	visual property (noun)
lack of sensibility	an attribute of vision
without sharpness or clearness of edge or point
the quality of lacking interestingness
a lack of visual brightness
the quality of being slow to understand