Slightly tangentially, there was a report in World Medicine (when I was a lad, so some time ago) about a man who had an accident driving home, he couldn't remember the accident at all, it was thought to be retrograde amnesia, but then he said he often arrived home without remembering the drive. It transpired that he drove past a stand of trees, and at a particular time of day, the sun shining through the trees could cause a strobing effect in the cockpit of the car inducing a mild seizure - he had no prior history of epilepsy, but further studies showed that he was susceptible.