can spiders see?

we have a garden-guest in our backyard: an orb-weaver spider.

and it knows me.

each morning (after sunrise, mind you, so i don't run into its web), i pass by it and it scurries away after it sees me. it's mildly alarming, but i figure it's doing the garden good. (i'm pretty sure.) and, hey! the spider in "charlotte's web" was an orb-weaver. that means it can't be all bad, right?