I drink caffeine and it has no effect on my dry eyes and neither does eating more safe starches. I started eating less carbs recently... back to mostly VLC with a few safe starches throughout the week and I still have dry eyes no matter what my carb level is. I am hoping vitamin C helps, but I also think it's environmentally related and possibly genetic.
I added that amount, too, and started gaining weight and didn't feel good with that much so I reverted back to low carb with a few starches throughout the week and feel much better.
Dry eyes are direct correlation to how well you sleep. If you find yourself waking up frequently during the night, it's likely your stress hormones are elevated causing night dehydration.
Increasing carbs would help with this, as well as improving cataracts through increase of co2. Breathing in a bad before sleeping seems to help me as well.
Tired eyes, like our tired lives