My experience is if your eyes are stinging, you are way too exposed to the fumes. Using a fan blowing across the workbench, and avoiding using large amounts of thin CA, should keep you below that exposure level.

For me, before I started using a respirator, the next day I'd have almost exactly what a cold would do, runny nose, congestion, itchiness that would last a day or two. At first, I thought it WAS a cold, but after a half dozen experiences, I knew it couldn't just be a coincidence. Now I use a respirator, and stop and let things clear out if my family notices fumes coming out of the workshop.