Cujo is 5 yrs. old and has developed terrible allergies. After several days of sneezing, scratching and gunky eyes I took him to the vet. They gave him a steroid shot and told me to use Banadryl. He's quite a bit better but not totally cured. I know what you mean about the eyes, Cujo's eyes are driving him crazy! I absolutely believe his allergies are from all the new green grass and plants as we haven't made any food changes. I'd say the steroid shot made him 80% better!
Good luck!
PS-We're practically neighbors!