It’s a commonly commiserated problem because it impacts different people to differing degrees. Some are actually impaired by the light, and I imagine others just complain because they have to avert their gaze to the edge of the road but don’t actually lose their night vision. But if you have ever had LASIK, have a vitamin A deficiency, a genetic condition impacting vision, or a more common condition such as diabetes or cataracts, the way light passes through your eye is different than normal and bright lights at night can blind you. You may not notice that you don’t have particularly good night vision unless you are around someone who does. If in doubt, it probably doesn’t hurt to get it checked out, especially if it didn’t bother you when you were younger but does now.