In the dark my eyes become irritable and sensitive to light

In the night I wake sometimes with sensitive eyes.
Please excuse the following flop of words as I attempt to explain what I mean by "sensitive" eyes.
The room is always dark.
The time of night fluctuates.
I wake from a dream and am aware of how badly my eyes are sensitive to light (in the same way as coming out into a sunny day from inside a building).
My eyes are still closed at this point but are acting as if I am staring directly into the sun.
I must open my eyes to settle my mind.
The darkness helps.
I close my eyes and return to the blinding uncomfortable feeling.
Flashes of light fill my closed eyes as if lightning is striking just on the other side.
I open my eyes and close them numerous times to clear the flares.
This can go on for up to an hour.
I fall asleep and forget to write it down.

This is not a new occurrence.
I have a vivid memory of a younger me (less than 10 years old) in the bed at my grandmother's house. I am there and so is my aunt and cousin.
I have one of these light shows happen and take it as a sign from God.
I freak out.
As I am screaming and running to the bathroom to get away from the reach of whatever ethereal presence just wanted my attention, my aunt looks at me with a "what on earth is going on" look.
I should explain that my grandmother was an extremely religious individual.
It was not uncommon to get up to use the restroom late in the night and find her reading the bible at her kitchen table.
My less-than-developed brain thought God himself had reached down through my eyelids in a blinding display of power and that her house was a beacon for all things unexplainable and downright freaky.
I now know it's not God doing this to me.
My running theory is that I actually sleep with my eyes open and that after many hours they become so dry that closing them is painful.