Right now, she's running with no filters, which has me quaking in my boots, but the images are crisp again.
sweat it not, my friend. minor scratches will never show up in an image and if you hit it hard enough to crack the front element, it's gonna get cracked whether there's a filter on it or not.
this picture:
was taken with this lens:
and these pictures:
were taken with this lens:
multiple examples in this articleand more here