Damn it.
Having an ocular migraine episode. They always come in clusters for me. Makes reading almost impossible, but fortunately it's finally starting to fade. Maybe?
Definitely a longer lasting episode. Usually they come and go within a few minutes. Starts as a subtle flashing on my periphery then I get colorful jagged and blocky lines that "tears" across my vision. Somewhat like visual artifacts, but far more pronounced because they obscure my vision partially, or nearly completely in one eye.
@nevikjames Classical migraine aura. They typically present as a small "hole" (scotoma) at the centre of vision, making reading difficult, then widen into scintillating coloured zigzags. These normally retreat to the periphery in about 25 minutes. Thought to be a kind of electrical storm of random neuron firing which progresses in a wave across the visual cortex of the brain.