Hi Tim,
I don't know how well the track you race at is lit at night, but I wear my sun glasses even after it gets dark. I can see the lights ok, but at night the amber lights tend to "shock" my eyes. I wear glasses anyway, but use a clip on style amber shade.
Some of the tracks I run at are not lit well enough to wear shades past the starting line. I have seen others use a full face helmet with a amber face shield and flip it up as soon as they're away from the starting line.
Of course, lately, I haven't had to worry about that. Loaded up before dark
Brian