Why do I have double vision when I drive at night; especially looking at headlights?

Possible cataract. If you are experiencing what you describe as "double vision" only at night, especially when looking at headlights you are more than likely sufferring from "tmb." this stands for "too many birthdays." you are more than likely of an age where you might have aging cataracts in one or both eyes. The reflection of oncoming headlights off of the cataract can result in the symptoms that you describe.