Here is a quiz from DMV written test.
A-1) Some traffic signs are less visible at night.
A-2) More vehicles are on the road at night.
A-3) The distance we can see ahead is reduced.
A-4) Street lights tend to blur our vision.
The answer is..
A-3) The distance we can see ahead is reduced.
Please don't be too confident of yourself while you are driving at night.