Thanks for that information.
There are two possibilities for what is happening:
2. Upper respiratory tract infection (URTI or cat flu)
Because Corazon is reasonably well otherwise and this is confined to her eyes I suspect it may be allergic. Perhaps contact with a plant pollen or similar or maybe an insect/spider bite. Cats will investigate all sorts of nooks and crannies and can contact a wide variety of allergens. But of course this could just be the early signs of URTI and that may require some more general medications and/or specific eye medication. Your vet will of course look after that side of things when he/she sees her.
In the meantime we can provide relief for her in two ways. First you can bathe her eyes with any human (non-medicated) eye bathing solution if you have any on hand. But a good alternative is a saline solution. You can make up your own by dissolving a teaspoon of salt in a pint (600 ml) of water. It’s best to have boiled the water first and allowing it to cool. Wash the eyes liberally. It’s quite soothing.
If you have any Benadryl Allergy (diphenhydramine) available that is quite safe and will relieve the discomfort as well as reduce the swelling. Ensure it is not the combination product (Benadryl Allergy and Sinus). The dose for cats is 1-2 mg/lb. Benadryl comes in a variety of formulations and strengths. If you are unsure please tell me the strength of what you have and Corazon’s weight and I’ll advise you.