Loss of vision in darkness.

[Berline]

I woke last night -bedroom was dark- for about a microsecond I seemed blind, I blinked and could see again.
My vision is fine now with NO issues at all.
No floaters, no flashes, no headache, no dark curtain etc.
Should I be concerned?
It may sound silly but it's bothering me.
Any ideas what this could be?

Your eyes adjusting to the light is all

get your eyes checked.
I can't see in the dark on one eye without glasses. I'm far sighted.

That's normal, it takes time for your dark vision (scotopic) visual sensors to kick into action.