Q and A: Can a Blow to the Head Render My Character Blind?

Q: My male character hits his head on a wall, rendering him blind. How long would he be blinded for, once the swelling that caused it goes down? Any long term effects, such as headaches and that?

Michelle Cunin, Alliance, Ohio

A: Blunt trauma to the head if it is severe enough to cause a cerebral contusion (brain bruise), where by definition there is some degree of bleeding into and swelling of the brain tissues as a result of the trauma, can easily cause a malfunction in that area of the brain. If it is the area of the brain that controls vision, your victim could easily have blindness. We call this cortical blindness since it arises from the cortex of the brain and not from the eye or from the optic nerve. In other words the loss of the ability to see comes from the brain itself. The visual cortex, the part of the brain that controls seeing, is in the very back of the brain in what we call the occipital lobe. In order for your victim to be completely blind both halves of the brain would have to be damaged otherwise he would only lose vision to his right side or his left side but not both. But this could easily happen with a blow to the back of the head or can occur after a fall where the back of the head strikes a wall, the floor, stairs, or almost anything else.

 

 

If the injury were severe enough to significantly damage the optical cortex then his blindness could be permanent but in most cases once the bleeding inside the brain stops and the swelling resolves, vision will return. This could take a few hours or many weeks so you have a broad range to consider when constructing your story. Any of these are possible.

The victim’s blindness might be complete or only partial in that he might be able to see shadows and shapes or one half of his visual field might be clearer than the other. This later situation would indicate that one side of the brain was damaged more severely than the other. If it were the left occipital lobe that was more severely damaged then the right half of his visual field would be the most affected. If he were struck in the left back side of the head, for example, he could lose vision of the entire right side of his visual field. It would appear as if a line had been drawn down the center of his visual field and everything to the right of the line would be black while to the left all would be normal. But since you want him completely blind it would require injuries to both occipital lobes.

Whether his vision returns or not, he could suffer from long-term headaches, dizziness, poor balance, and a few other symptoms but he could also return to complete normalcy. These symptoms could last a few days, months, or forever. All is possible.