Jackson's and some other species have a "temporal" gland at the corher of the mouth. Yes, they can get heavily infected and this can spread along the cheek toward the eye too. The gland itself needs to be flushed thoroughly as the infections can be very hard to clear. Systemic antibiotics in addition to clearing the gland are probably needed. I've also read that increasing the vit. C level in feeder gutloads can help prevent recurrance.