You could add in some antihistamine eye drops as my blepharitis is always worse when pollen is high.
I was diagnosed with blepharitis a few months ago, I didn't know high pollen could possibly make it worse. Will have to check that out when it flares up again.
My GP told me to put some drops of Johnsons baby shampoo in warm water and with cotton wool run along underneath the eye, from inner to outer edge a few times, 3 x day, and it will clear it, and it seems to work.
I'm not sure if doing this will help you Dierdre, you could give it a try for nothing.