Styes and redness go together. Styes are in most of the cases caused by staphylococccus. If I were you, I would see a dermatologist or a descent GP. Your eye itself might be fine, but styes are on your eyelid.
As far as eye problems caused by Bartonella: many of them. Floaters, stinging, problems focussing, blurry vision, pressure on the eyeballs, conjunctivitis, etc... I have them myself. I think that they will go away once the infection is totally under controll. Cause up until now, I haven't seen any change after many months of treatment.
Hope this helps
Lyme & Bartonella. Sick for about
19 years (34 now). Started treatment August 2012 with abx (ILADS protocol, different combinations) + Buhner's Core Protocol. Leaky gut, heavy metals, EBV, XMRV, erythema nodosum, Hodgkin's Lymphoma at 15, Lyme arthritis, many neurological symptoms, food allergies/intolerances, histamine/chemical intolerance and much more.