Val: Technically you are right. Integra’s/RSX have projector lenses already in the housing that do reasonably well with an HID bulb behind them. This allows you to buy a ballast bulb combo that plugs directly into your OEM harness, which is what we are referring to. The light cutoff should be just fine that way.
If you are retrofitting into a vehicle without OEM projectors, then yes you’ll have to figure out a way to fit another lense in there, otherwise you are negating the benefit of an HID setup (clear intense light, wide beam dispersal perfect cutoff).
By the way get off the PC and GTF back to work. 