My brothers and I would always fart on each others pillows in hopes of administering the infamous "i-farted-on-your-pillow-and-gave-you-pink-eye" joke. None of us ever got pink eye. While I can see it being possible, as long as your eyes are doing their job and flushing out toxins and irritants via tears, then you shouldn't get pink eye. I think the science behind it is that when you fart, microscopic shards of dry fecal matter fly out of your anus and onto the pillow, where the victim may lay their head; when they are on said pillow the particles fly around and get in the victims eye, causing irritation and bacterial growth. But I'd definitely still recommend farting on any pillow you can find.