______ caused Robert Edwards’s blindness.

Robert Edwards was blinded in an automobile accident 9 years ago. He was also partially deaf because of old age. Last week, he was strolling near his home when a thunderstorm approached. He took refuge under a tree and was struck by lightning. He was knocked to the ground and woke up some 20 minutes later, lying face down in water below a tree. He went into the house and lay down in bed. A short time later, he awoke; his legs were numb and he was trembling, but, when he opened his eyes, he could see the clock across the room fading in and out in front of him. When his wife entered, he saw her for the first time in 9 years. Doctors confirm that he has regained his sight and hearing apparently from the flash of lightning, but they are unable to explain the occurrence. The only possible explanation offered by one doctor was that, since Edwards lost his sight as a result of trauma in a terrible accident, perhaps the only way it could be restored was by another trauma.