A careful history, artificial tears, tear duct pugs, omega 3 use, environmental modification, and if needed
Restasis (the new Xiidra is wildly expensive) can handle 99% of the patients. Below is a previous post on dry eyes:
General Information on Dry Eyes-Now known as Tears Dysfunction Syndrome or Ocular Surface Disorder.
a Schirmer test of zero indicates that you have severe dry eyes.