I'm with Gary Lager. It's not so much of a problem, depending generally on your landing technic. Some people, especially young/unexperienced pilots seem to have problems without. It all depends how much of depth you can perceive if your tarmac is not illuminated in front of you. Me I use the radio altimeter count down a lot, so I don't really need the visual cues of an approaching tarmac that much. It's maybe a thing you have to train an odd time, first with only one landing light out, then you get the feeling.
Fly safe,
Dani