Brief Answer:
Can be Migraine with aura.

Detailed Answer:
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Most likely as sparkling distortion is associated with headache and dizziness it can be aura of migraine.Aura of migraine is usually visual.A visual aura is like an electrical or chemical wave that moves across the visual cortex of your brain. This visual aura may expand into a sickle- or C-shaped object, with zigzag lines on the leading edge.
Second possibility is that they can be because of floaters. Floaters are dark specks in the form of dots, circles, lines, flashes or cobwebs that seem to move across your field of vision. Floaters are small clumps of visible material within the vitreous. Usually they remain clumped but in old age bits of debris are discarded by the vitreous humour or retina that causes protein (connective tissue) to be released.Hence crystal-like deposits may form in the vitreous and interfere with light passing from the front of the eye to the back.These floating particle within the vitreous are seen as shadows in retina.The vitreous sometimes pulls on the retina. This may cause you to see flashing lights or lightning streaks, even though there aren't any such lights present. When the vitreous separates from the retina.
Detailed retinal examination. slit lamp examination of eye should be done by opthalmologist.If its not due to eye a neurologist should be consulted to rule out possibility of Migraine with aura.

As far as dehydration is concerned it can precipitate an attack of migraine,Thorough investigations are necessary before reaching a diagnosis.


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