When I have a bright light in my eyes at night, I lose my balance. Anyone have that problem also?

Most people have a strong sense of where their body is in space and what position they're in (vestibular sense). More people than you'd guess, don't. People who don't have a working vestibular sense can still keep their balance as long as they can see what's where. If something makes them totally unable to see where they are (as in a bringht light is shined in their eyes) then they don't have a sense of balance and will be dizzy and maybe fall.