John K Jordan
A power filtered face mask like often used for woodturning can keep most of the very fine dust away from your eyes. Better is a 3M industrial full-face respirator (available from Amazon) - I use them mostly if I need to spray chemicals.
For walnut and some other species, I find a mild sensitivity is triggered by particles so small you can't even see them, not necessarily by sawdust I can see. If I can smell the walnut it's too much. A room air cleaner can help clear the shop while you are out.