I'm using the same thing, along with Refresh single use liquigel (preservative free, little plastic one use eye drops) My right eye is still feeling incredibly dry.

I quit using the Singulair...I was only taking it temporarily for some allergies, and I dont think I'll use it again. I quit taking the Singular on thursday, so you would think that it's metabolized out of me. But, my eye is still dry, altho it's not as bad as it was last night.

It is starting to freak me out some tho. Wondering if it's a new thing with the optic neuritis.