There was a change after the last major patch that really bugged me, an effect that made grass look darker when hit by a shadow. It looks fine during the day but at night the grass is just entirely black and completely contrasts against the ground around it, and it looks awful. At first I assumed it was simply a bug with the shadows, but apparently it was meant to look this way, and I really, really don't like it. It makes the game almost unplayable for me at night because I am constantly distracted by the huge, unrealistic patches of pure darkness on the ground. Is there a way to stop all of the grass in Skyrim looking like it's made from dark matter whenever night falls? Is there a way to make it look like it did before the patch is basically what I want to know.

Actually it is a bug: http://www.gamesas.com/topic/1370538-grass-shadows-are-buggy-hurt-performance-and-cant-be-disabled/
Nothing you can do except to complain like me for Bethesda to fix it.
You should look at the grass shadows during foggy and rainy weather as well. Prepared to have your eyes bleed