I know this is long but please bear with me, trying to provide context for why this is such a volatile situation with my neighbors.
I live in a very urban area, on a street with single family homes. We are between a train and a busy major road. Our city also has a very aggressive and large homeless population who will torture and kill stray animals (without going into detail, I know this through my job). There are also loose large dogs in my neighborhood regularly. Most concerningly, we have a serious coyote problem across the city, and pets are regularly killed by coyotes. Coyotes will be on the street in broad daylight. I found one of the street cats killed by a coyote while walking my dog at night last year. My across the street neighbors have always had a female cat with no collar that hangs out around their home and yard. They have 2 dogs that live inside, one is an unneutered husky who occasionally gets loose and runs into my yard.
I started interacting with this cat probably 4 months ago. She would be hanging out on the sidewalk in front of her house and I would pet her on my way to the train and coming back from the train after work. She started taking a liking to me and getting excited when I would come around. I also got introduced to some of the occupants of the house this way. We had very friendly interactions and would chat or say good morning as I petted the cat. They told me she was a stray that started hanging around their house about 4 years ago, so they started feeding her. At that time she never wore a collar. Note that I never at any point went into their yard, this all occurred on the sidewalk which is city property. Additionally, the cat always had a clouded over, enlarged eye. I've never owned a cat so I wasn't sure what the deal was with her eye. She doesn't seem old so I thought it was odd.
The cat would roam around the street daily so she started coming to my yard and waiting on my porch, often in the morning before the people in her house would get up. I would go have my coffee on the porch and she would sit on my lap and get petted. Then when I left for work I would either just leave her in my yard, or a few times I would pick her up and deposit her into her own yard on my way to the train (I'd rather carry her than have her cross the street alone, people drive crazy). My husband bought a few cans of wet cat food at the grocery store one day because he apparently thought she was a complete stray? I explained that she does get fed at the neighbors house. But then we just had cat food we had no other use for so I put a little bit on a paper plate maybe 3-4 times a few days apart and set it out for her (not a full can, I would split the cans and refrigerate the rest in between). Apparently you aren't supposed to do this with outside cats but I didn't know at the time.
A bit after I last fed her, two of the neighbors (including an older woman who is evidently the mom, I had never seen or met this woman) came over and yelled at my husband while I was at work. The cat was chilling in my driveway, I had been at work for at least 6 hours at this point (I was working 10-12 hours days at the time, not home except for early mornings and nights). My husband tried to be friendly and cordial (I watched multiple times on the ring camera) and they maintained an aggressive tone and said I was "disrespectful" and trying to steal the cat. One of them said "what if we tried to steal one of your dogs" and at this point my husband pointed out that our dogs live entirely inside so this comparison did not make sense. They took the cat and went home, of course she was back a few hours later when I got home. The next day she was wearing a collar (no tag).
The cat continued to visit daily and I would just pet her out front, no feeding. One weekend day she came and sat on my lap while I was reading. As she was sitting, my neighbors were all in a car that drove by and started yelling at me out the window and calling me "cat thief" and saying I was feeding her. I just said, no I am not feeding her she just comes here. They drive off and so I decide I'll write them a nice note explaining that I have stopped feeding her, and she just comes here on her own. However as I was writing this, cat sitting several feet away, the car came back 15 mins later and the older woman and her husband were the only occupants. She got out and came to my porch and started screaming at me. Both my husband and I were more polite than we should have been and I kept saying, hi I was just writing you a note, can we have a conversation about this? She just kept screaming random things for probably 10 minutes as I tried to de-escalate. She said I stole the cat off her porch? I did firmly say that never happened. Eventually she tried to grab the cat and it ran from her behind me. I ended up going inside and I think she did grab the cat after that and left? I never gave them the note, there is no point. My plan after that was just to call the cops if any of them came in my yard again, but we've had no interaction for probably 2 months.
So I started having my coffee in the backyard where the neighbors can't see me. Of course the cat comes every day to hang out with me. She is there like clockwork and if I wake up late she sits and waits for me. I have her a little hammock thing and a few toys back there, and I give her fresh water twice a day. I have never seen a toy at her house, she didn't know what to do with them for a while but now she plays regularly and asks me to play. I don't think she gets enough water at home because she is thirsty when she comes over. I brush her and clean her face daily, including all the discharge from her bad eye. She is truly the sweetest and cuddliest cat I have ever met, and she tolerates perfectly being cleaned, picked up, etc. She sits in my lap every morning and makes biscuits on my robe and will even rub her face against my cheek. One time it rained and I found her soaked and freezing hiding on my outdoor shelf, I made her a shelter with a heated blanket and dried her and warmed her up. We live in a hot area so she wouldn't be too cold in winter, but we sometimes have heat over 100 and I always fret about her and put ice packs in her mat outside.
The issue I am posting about is her eye. It has been getting worse and more swollen over the past few months. She can't see out of it at all. I have been trying to figure out how I can help with this. First of all I think the eye is probably beyond help and needs to come out. It's so bad and she can't see out of it at all. If I thought drops or something would help it I would just sneak her in for an appointment early in the morning and get them. But I can't exactly get an eye removed without the neighbors noticing and losing their shit.
I don't think she gets any kind of vet care whatsoever, she has clearly had a flea once or twice so I don't think she's getting basics like flea and tick meds or vaccines. Her collar came off at some point and they didn't bother replacing it (it never had a tag anyway so not sure what the point was). I thought the eye was severe glaucoma, but recently I spoke to someone who used to do cat rescue and she said it's a virus or infection, that could spread to her brain if left untreated. That really freaked me out and I feel like I have to do something now. I know I could just stick her in a carrier and take her in without issue, she's very chill.
I have basically unlimited budget here (and I know my neighbors definitely do not). I will pay whatever is needed for this cat, I love her. But I'm not forking over several thousand dollars for eye surgery and then leaving her outside as coyote bait. If I get her a surgery she's coming to live in my house and be safe, full stop. But I'm afraid this is going to cause a situation where my neighbors may resort to physical violence and harassment, and try to hurt my small dogs. She's being medically neglected at this point, and I would be justified in reporting them to animal control, but I don't want her to end up in a kill shelter.
What do I do here? I'm at the point where seeing her eye causes me so much anxiety every day. I can't let her suffer like this, she is such a little angel. I have included pictures over time of the eye (it's nasty in earlier pictures but now I clean it every day so less crust).