This pic is from four weeks ago. Kitty appeared with a suddenly swollen right upper lid. It took four or five days to subside, then all was well again. Today, she's got a swollen left upper lid, looks just like the pic.

The cat exhibits no other symptoms- runs, plays, meows, seems perfectly content. When this happened last month, the wife and I thought it might have been a spider bite. Like all cats, ours sleeps on the floor at intervals. I doubt it's a spider now. The wife has been trying to save money on cat litter and says the stuff she's using now produces a fair amount of dust when she changes it out. Seems like dust would cause problems in both eyes, and not just one upper lid or the other.

It seems like to comes down to either something biting her, or an adverse reaction to something.

Any ideas?

Dump the dusty litter before it does get in both eyes at the same time! Sweet looking kitty, BTW.

Yes, we're going back to premium litter. In the interim, looking for answers. I don't think it's the litter.

Looks like a little scratch on the lid by the inner corner of her eye. Does she play or fight with any other cats you know of? My two are always scragging each other and leaving little digs. I just put a spot of triple anti-biotic on them and the go awawy.

Is she indoor only?

We have two 17 year old brother and sister cats and all i have ever used is cheap un-scented litter in two enclosed boxes changed out weekly and other then a little dust when filling nothing else bad.

No contact with cats or any other animals besides us. Indoor cat, gets short, supervised visits to the outdoors- walks around the outside of the house, sniffs everything. Runs, plays- the usual cat stuff. Never leaves our yard and never left alone while outside.

Any kind of toxic or thorny plants around?

I know just about all plants can be bad but anything she’s getting into thats new?

Ours go after anything alive or dried out.

Not that I know

Closest thing I saw like that was my wife's eyelid this morning. It was swollen from allergies.

Poor kitty. Hope it gets worked out. A visit to the vet might be in order.

She might have a ingrown hair in the lashes…my moms chow got an ingrown lash and it looked like that…the vet managed to dig it out and he never made a peep about it.

Hope you figure it out..it looks like it hurts

Are you using plastic food or water dishes? Some cats can be allergic to the materials in plastic dishes and skin issues can result.

Could be blepharitis- inflammation of the eyelid. Many things can cause this- infections, allergies, tumors, irritants, bites or injuries, chronic rubbing.

Treatment and prognosis depend on what the actual cause is.

Is she worrying at it? Does it bother her in any way? How quickly did it appear- you say suddenly, do you mean hours, minutes, and did you happen to notice what direction she sauntered in from? Is the swelling warm to the touch/ will she allow you to palpate and see if there’s any sign of a break in the skin?
Temp normal, and no other behavior changes or diet changes you’ve seen? Bowel movements, eating drinking all normal?
The questions are trying to help think about what might have possibly occurred..hopefully slabsides will swing in and comment soon.

My guess would be an allergic reaction to something in the new litter.

I had a dog once with something that looked similar - it was mites brought on my stress

Those are areas where cats will rub to leave saliva deposits (marking). My first though is that you may have tried a new cleaner in your house or had the carpets cleaned and you are seeing an irritant or allergic reaction.

BTW many years ago I used to use a bit of dish soap and water to clean my kitchen floor. Then one week I picked up some "kitchen" cleaner at the grocery and tried that. Cat ended up with a hand sized area bald area on his side. Took him to the vet and he asked about any cleaner changes or carpet cleaning. Ended up going home and rinsing the kitchen floor 4 times with water and that cat got to wear the neck portion of a turtle neck sweater that I hated for 3 weeks.

Our cat started getting lesions like you've shown. If your kitty is drinking out of a plastic bowl try switching to stainless steel or glass. Our cat had an allergy to plastic and it cleared up within days of the switch.

I'm pretty sure Lysol, perhaps other cleaning/disinfecting products, can cause eye or respiratory problems with cats.

Based on the history, I suspect some unknown bug bite, which resulted in a localized allergic reaction that resolved in a few days (1st episode 4 weeks ago) without needed treatment. Same thing with the current reaction on the other eyelid. Hopefully it will spontaneously resolve like the 1st one. Infection (eyelid / periorbital cellulitis) wouldn't resolve without treatment. Of course, I say all this based on human anatomy & physiology, which could be completely wrong, as I know nothing about animal physiology.