Aren’t all of the decks lit up?
Just came back on one. 10 days. Beautiful night ocean with moon light reflection. No light on any balconies unless the cabin occupant turns it on. We were on deck 7 and could see 6, 8 and 9. No lights.
From what folks say they are designed not to be able to fall off of.
Frankly balcony cabins are not worth the higher cost. There are a million places in public areas to soak up the sun or the breeze. But if one wishes to be naked while sunbathing, may be then balcony is useful.