What is the ruling on calling one's wife "light of the world" (نور الدنيا) as a term of endearment and an expression of love?

The title "Illuminator of the World" should not be applied to a person, as its meaning implies that the one described acquired light from the descriptor. It is inconceivable for a single person to illuminate the entire world. This title contains exaggeration and excessive commendation, and it is disliked to use titles that involve such commendation. Other permissible titles offer sufficient alternatives to this one.