The only drawback from this that I see is that PCs will use this tactic 100% of the time against enemies. "Get the hood lantern ready, shield your eyes guys, and....GO" All enemies blinded, PCs attack. My guys would abuse the crap out of that.As I said. Too many races have DV. With level restrictions I would not mind, but since those days are over, then there must be some drawback to DV. The drawback that I enforce is if a bright light source is brought up suddenly, you are blinded until you make a con save (at the end of your turn) to end the effect. The save is usually easy at 13. Most characters only need a 11 or better to save.
No save is required if you are in the dim light radius. This alone makes up for interesting tactics from the players and the monsters.