I am sorry Frankie is not feeling well.
She most likely has an URI:
All cats carry upper respiratory virus on their own fur. Cats that live together become immune to the carried strain but as soon as the bacterium is exposed to another cat or an older cats immune system weakens, it will infect them. If this boy was exposed to other cats she likely contracted it from them or stress.
Feed him very odorous food so he can smell it and will keep eating. If he gets dehydrated, give her a few droppers of unflavored pedialyte througout the day to hydrate him and balance his electrolytes.
He can have an OTC called clor-trimeton - a quarter tablet every 12 hours if she is congested.Get it at any drug store. You can also take him in a steamy bathroom where you have run a hot shower to break it up.For the eyes get Terramycin ointment. some pet supplies have it but call first or order from http://www.revivalanimal.com/
If she develops any colored mucus that means the infection has turned bacterial and will respond to an antibiotic.Some vets script one even if it is viral to prevent secondary infections like pneumonia.
Please let me know how he is feeling. If you get worried I will always be here to help further.
I hope he feels better very soon.