Hi Beoman,
I got something resembling this in certain ways, some time last year, mainly at night after waking up. I posted a few comments on
Duncan's blog about this.
Some kind of energetic experience, I guess. Third eye overload or out of synch or something

Or else, a neurological condition - some types of migraine don't manifest as pain but just have the "
Aura", i.e. the disturbance of vision and so on. Migraine is quite common, around 10% of the population.
Or a combination of the two. If it worries you, go see a doctor about it.
Cheers,
Florian