This is the 9039th most frequent German word.
lich
In German, "lich" is not a standalone word but rather a suffix meaning "-ly" or "-like," used to form adjectives or adverbs, e.g., "freundlich" (friendly).
In this sentence, "Licht" is used as a noun meaning 'light', referring to the physical phenomenon.
Das Licht der Sonne erhellt den Raum.
The light of the sun illuminates the room.
The word "wichtig" contains the suffix "-lich", forming an adjective to denote importance or relevance.
Die Schülerin hat eine verständliche und nachvollziehbare Meinung geäußert, das war sehr wichtig.
The student expressed a comprehensible and logical opinion; that was very important.
Here, "licht" is part of a compound adjective "lichtempfindlich" indicating sensitivity to light.