itchy cat eyes

I have taken my cat to several vets and no one seems to be able to help him.  He is 15 years olds and healthy other than he keeps scratching his eyes to the point that they bleed and get infected, this has been happening for the past 2 years.  He has to wear a cone 24 hours a day.

Did the vets consider allergies? What are you feeding him? Are there any environmental changes that happened 2 years ago? Poor baby.

He is eating the same food that he has eaten for 15 years and nothing has changed in the house.  The different vets have given me ointment to put in his eyes and it helped and then it quit working, another vet gave him steriod shots and they helped for a while (can't keep giving him steriods shots they are bad for his kidneys etc) another vet gave him antibodics shots and pills. 

The itching seems to disappear for a month or so and then when the nice weather came I opened my window above my computer desk and he was laying on the desk, that night he started scratching at his eyes again.  I suspect that it is some type of allergy.  The last vet I took him to also suspected allergies but gave me nothing for him but antibodics.

Food allergies actually develop over time, so you can't rule that out if he's been eating the same food for 15 years.

I don't see how antibiotics would help with allergies. I have heard of antihistamine use for cats with seasonal allergies. That's something you could call and ask your vet about. If he does suspect allergies, would he prescribe antihistamines or something else for them?

If that doesn't work, you could try a diet change on your own with a novel protein (something he's never had before, like lamb or venison or duck).

 A common cause for cats with itchy eyes is feline herpes virus. L-lysine is a natural amino acid that can work wonders in some cases. It stops the virus from replicating. Of course if he has an infection too, antibiotics are needed for that.

Is L-lysine an eye drop, does my vet prescribe or can it be purchased over the counter?  I feel so bad for my cat, he is in agony with the itching.

L-lysine comes in a powder either the ones especially for cats or you can get the capsule for people and open it and use that. If it gets bad, ask the vet about giving Zyrtec for allergies. DON'T give it without speaking to the vet first but this helps lots of kitties with allergies.

It is available in a flavored gel at some vet offices. You don't need a prescription and it can also be purchased in any pharmacy, health food store, amazon.com, and some pet stores sell it in treats for cats. I have used the treats and capsules ( the same ones sold for people). You can give him 500-1000 mg while he is having a flare-up. I just open the capsule and mix it in their food. They eat it no problem.

There are lots of threads about it on this site if you do a search up top. If he has signs of infection he will need antibiotics too.

I hope he's feeling better soon

At this time he does not have any infection, the cone helps to prevent him from being able to scratch his eyes somewhat. (sneaky little guy somehow gets around the cone sometime). 

Thank you so much for your help, it is greatly appreciated!!

I thank all of you for your help, it is much appreciated.  Will try the L-lysine and will let you know how he does.  THANKS AGAIN!!!