Over the past 2 years I have probably had ~20 episodes of scintillating scotoma or ocular migraines with not pain.
It starts as a small area of loss of near center vision. Then I develop a small zagged, geometric bright, shiny silver arc which grows and grows to involve the periphery of one side of my vision (involves both eyes equally so this is probably not an eye problem). It then fairly quickly resolves. Sometimes I am tired for 15-20 min afterwards, but recently not usually.
Seen opthalmologists which don't offer any help.
It does not seem to be related to anything more serious, so DON'T WORRY !