Setting is modern; there is magic, but it isn't going to fix the problem (in fact, she's blinding herself for magical purposes). I can think of/look up any number of ways to inflict sufficient trauma that she'd lose an eye; what I'd like to know is whether there are any options that would involve a minimum of complications. In other words, no infection, preferably no need for surgery or a hospital stay; she just loses the sight in that eye. (Which isn't to say that I need the experience to be painless or pleasant. I'd just like to avoid, or at least reduce, the necessity for professional medical intervention.)
Searching for "causes of blindness" and "non-traumatic blindness" mostly gets me things like cataracts and glaucoma, which aren't exactly self-inflicted. The best prospect I've found is methanol (aka wood alcohol), but I don't see a way to make that affect only one eye. I'd love suggestions for other options. Thanks!