The spell continual flame (p. 227 of the Player's Handbook) is a touch spell. It does not offer any parameters as to what qualifies as a target other than it has to be an object. In theory you could touch an opponent's helmet and a flame would spring forth, potentially blinding them (with no save and no attack roll).
Whereas the light cantrip (p. 255 of the Player's Handbook) specifically states:
If you target an object held or worn by a hostile creature, that creature must succeed on a Dexterity saving throw to avoid the spell.
This leads me to believe the spell is working as intended.
Is there a rule or ruling that I am missing?