Insert this to your custom command line:
-ambient_factor 0 -no_emissive_light -fov 0.55 -spec_exp 16.7 -spec_point 0.6 -spec_static 0.9 -spec_tube 1
...that's what I'm running the game with.
-ambient_factor reduces the amount of ambient light in the game; I use value zero, you could start from somewhere like 60 and try to find the best value for your eyes.
-no_emissive_light cuts out the dim light that the ships normally emit in dark, which makes them visible on their shadow side. I don't like it so I disable it.
-fov sets the field of view value. IIRC the default value is 0.70, the smaller it is the shallower the field of view - in other words, it zooms in onto the center of the image, and causes things to look bigger. I use value 0.55, as you can see, but 0.60 or 0.65 are also good, and closer to retail field of view. The only problem with field of view setting is that it causes HUD target indicators to move somewhat anomalously, and that background stars start moving more erratically as well.
-spec_* settings affect the specular lighting settings. These values seem to work fine, so I haven't really experimented with them.
You can find more complete command line reference in the Hard Light Wiki, though...
