You should try this

I do this. When my eyes burn that's when I know its bedtime. I usually fall asleep within minutes

Gram’s story seems like a great way to produce a blind child with major cornea damage.

I get headaches if I blink too much. Honestly not much helps me sleep except having a long tiring day.

I tried this last night and it just bothered me

In my personal experience most of the people I know who (claim to) have insomnia have pretty lethargic lifestyles, and fall asleep really quickly on the odd occasion that they're physically active for a significant portion of a day.
So that might help too.

Why don't you test Granny's theory?