I'm with Gyro on this one...
I believe that Yellow lenses in general allow low light conditions to appear more contrasting and thus somewhat clearer.
Folks used to wear old yellow tinted shades for night driving, it takes the edge off bright lights and makes the apparent contrast between the darker areas that bit sharper.
I use yellow lenses for all conditions bar v.bright sunlight when I've got an old pair of flex 7s with a blue tinted lens, easier on my poor eyes.
Chimp