Can continual flame be cast on an opponents helmet to blind them?

The Spell Continual Flame(p227 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 opponents helmet and a flame would spring forth. Potentially blinding him. (With no save and no attack roll).

Where as the light cantrip (p255 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?