What are the most common kinds of visual problems after a brain injury? Are these vision problems temporary or permanent?
The two big categories of visual difficulty after a brain injury are visual acuity loss and visual field loss.
Let’s start with visual acuity loss. If a person wears prescription glasses and takes them off, he will have a loss of acuity — or clarity. With brain injury, people can have a relatively small visual acuity loss or significant loss.
Visual acuity loss results from damage to the eye, the nerve fibers that carry signals from the retina in the eye to the brain, or to the visual cortex. This loss can sometimes be effectively treated with glasses, magnifiers, or electronic reading aids such as closed-circuit televisions. How much the loss impacts an individual’s life depends on the degree of the loss. Needing a small amount of magnification is in some ways similar to those of us who need bifocals. A need for more optical magnification than that can require different devices and training.
Visual field loss is a bit more complicated. Think of your visual field as a pie. Visual field loss is categorized by which part of the pie is affected.
- If you have hemianopsia, half of your pie — or visual field, either vertically or horizontally — is gone; you cannot see it.
- If you have quadranopsia, a quarter of your visual field is lost.
- If you have homonymous hemianopsia, the same quarter or half is lost in both eyes.
- If you have bitemporal hemianopsia, you are missing the outer half (or inner half) of both the right and left visual field.
Hemianopsia and quadranopsia are the most common types of visual field losses; but going back to the pie analogy, other types of field losses include loss around the edges of the pie or loss from the middle going outward. And, of course, there can be differing combinations depending upon the individual injury.
Visual field loss is caused by damage to the nerve fibers that carry the visual signal from the eyes to the visual cortex and/or connect operations between different parts of the brain.
Are these vision problems temporary or permanent?
Just like people, all brain injuries are unique, and that includes the process of recovery; so it is difficult to generalize. After a brain injury, once the person is medically stable, we will start visual rehabilitation. If the visual problems resolve, great; if not, we have a head start by starting that early. Vision is integrated into other problems that can occur post-TBI like muscular imbalance and vestibular problems (dizziness, imbalance, vertigo, etc.)
Can people with brain injury suffer from both kinds of vision loss?
Yes, people with TBI can suffer from both visual field loss and visual acuity loss. After all, 40-50 percent of the brain is involved in vision; so if a person’s brain is damaged in a specific location or several locations, there is a high probability that his vision will be affected in some way.
About the author: Gregory Goodrich, PhD
Dr. Goodrich received his PhD in Experimental Psychology in 1974 from Washington State University. His career with the US Department of Veterans Affairs began in 1974 and he is currently supervisory research psychologist (Psychology Service) assigned to the Western Blind Rehabilitation Center.
Please remember, we are not able to give medical or legal advice. If you have medical concerns, please consult your doctor. All posted comments are the views and opinions of the poster only.
Anonymous replied on Permalink
Thank you for your comments. I thought I was going crazy. But I realize now it is my brain!. I am 62 years old now, back when I was 20, I had a brain abbesses caused by an oral infection that was not treated with antibiotics . I have the size of a tennis ball missing from my right frontal lobe. Within the last two years my vision in my left eye has been getting worst in just my left eye. I am not sure what type of Dr to see for help.
Anonymous replied on Permalink
There was no mention of double vision which is what I have from my TBI. The vision itself is still really good but now there is two. LOL. I also watched a video from the snow boarder that was supposed to be a threat to Shawn White in the Olympics but he ended up getting a TBI while training and hit the hard packed snow giving him a TBI and that was one of the injuries in the TBI was double vision. I would like to hear more about that. I got surgery and can only obtain single vision with my head in a certain posistion looking forward but if I move my head a little out of that position then I see double. I have to go back to have the DR. mess with it again to get better results.
Pekka Tuohimaa replied on Permalink
Many years ago at the age of 14 ,I attempted suicide by over dosing on 100 mg capsals of Dilantin , about 30 or 40 of them. Luckily I survived but many days after getting out of the hospitals ICU ward, for about two months,every time I hit a hard bump while riding my peddle bike I would get double and triple vision and lasted for an hour or two and needed to sit awhile. NO vision problems since a right temporal lobectomy in 1988 but a weak left side persists and walk with a limp eve since. That was 30 years ago that I had brain surgery.
Kim Carrier replied on Permalink
I have a left tempraral lobe degeneration, I am having trouble with my eyes and balance issues. I want to thank you. I am sorry I bothered u. I was glad to know.