How to cut out Darkvision?

[UristMcRandom]

You can reduce Darkvision to see in dim light without penalty, but no darkness, and have Superior Darkvision being able to see in darkness.

Another solution to this is to make it so that night is dim light, not total darkness. Anyone who has taken a stroll at night knows that your eyes adjust, so there's not a terribly good reason why you should be affected with the blinded condition.

These two are my personal favorite solutions. In 3.5e, Elves, Gnomes, and Half-Elves had "Low-Light Vision," which allowed them to see twice as far in dim lighting as a Human could, while Dwarves and Half-Orcs possessed full Darkvision, which worked essentially the same as 5e's version. You could just convert the Low-Light Vision ability to 5e by removing the penalty for working in dim light, while still not allowing them to see in utter darkness without a source of light.