Fish oil helped me with that. (Coincidentally?)
(I'm interested because my sister has just had eye surgery and while she is still adjusting to her new vision, she said something about potential dryness)
Regular fish oil pills from Amazon or Walmart. My eye Dr recommended it. Just took a couple before bed.
For me the dry eyes started a year after the laser eye surgery. Really only night time was a problem.
The other thing that might have helped was installing a whole house humidifier.
Do you mean cod liver oil capsules?