Occipital lobe damage can cause a person to experience different vision problems after brain injury.
You’re about to learn the symptoms of occipital lobe damage and some helpful ways to treat it.
But first, let’s discuss the function of the occipital lobe.
Understanding the Occipital Lobe
The occipital lobe, located in the rear portion of the cerebral cortex, is primarily responsible for visual functions. It is the part of the brain where visual information is processed.
After it is processed, visual information leaves the occipital lobe via two major pathways: the dorsal stream and the ventral stream.
The ventral stream is a pathway that leads to the temporal lobe. It carries information related to object form, color, and recognition. Essentially, it helps the temporal lobe determine “what” you see.
The dorsal stream, on the other hand, carries information about where objects are in space. It flows into the parietal lobe, where it is further processed.
As you can see, the occipital, parietal, and temporal lobes interact closely together. Therefore, the symptoms of occipital lobe damage can overlap with those associated with parietal or temporal lobe damage.
Symptoms of Occipital Lobe Damage
The symptoms of occipital lobe damage revolve around vision and perception problems.
The most common symptom of occipital lobe damage is blindness and visual distortions, such as hallucinations. But there are several other symptoms a person can experience as well.
1. Partial Blindness
This is also known as visual field loss. It happens when only a portion of your visual field is lost.
Partial blindness can manifest in several different ways, including:
- Hemianopsia – Half of your visual field, either horizontally or vertically, is gone.
- Quadrantanopsia – A quarter of your visual field is gone.
- Peripheral vision loss – The outer edge of your visual field is lost.
- Central vision loss – The middle of your visual field is lost, but the peripheral vision is fine.
You can also develop something called homonymous hemianopsia. This occurs when the same part of the vision field is lost in both eyes. For example, the left half of your vision would be gone on both your right and left eyes.
2. Word Blindness (Alexia)
Occipital lobe damage also leads to an inability to recognize written words.
It occurs when visual information from the occipital lobe cannot pass to the areas of the brain that process language.
It’s similar to receptive aphasia, except it doesn’t affect the ability to understand spoken words. Instead, looking at a piece of writing would just look like strange lines and symbols.
3. Color Agnosia
Color agnosia is similar to normal color blindness. Except whereas color blindness affects color perception, color agnosia affects color knowledge.
With color agnosia, the mechanisms in the eye that enable a person to see color remain intact. But the person could not tell you what color they are looking at.
This means that a person with color agnosia would be able to pass a normal color blindness test, but they couldn’t tell you what color a banana is, for example.
4. Akinetopsia (Motion Blindness)
This rare condition causes a person to not perceive motion in their visual field. Instead, you might see motion as a series of stills, like something moving under a strobe light.
In severe cases, you might not be able to detect motion at all.
5. Simultanagnosia (Balint’s syndrome)
This symptom makes it almost impossible for a person to perceive more than one object at a time. It is common after both parietal and occipital lobe damage.
For example, a person with Balint’s syndrome who looked at a house would only see a door or a window. They would not see the whole house. They also could not see their fork if they were looking at their plate.
Other symptoms include:
- Optic Ataxia. Difficulty reaching for an object you are looking at.
- Oculomotor Apraxia. Inability to move your eyes towards an object.
A person with Balint’s syndrome would also be unable to read, because they could only see one letter at a time.
Treatment for Occipital Lobe Damage
To deal with occipital lobe damage, your best course is to start occupational therapy, which can help you learn effective compensatory tactics.
For example, people with word blindness can utilize strategies that many blind patients use to read, such as text-to-speech programs or braille.
In addition, some of the treatments for traumatic brain injury eye problems might help you recover some of your vision.
Occipital Lobe Injuries: Key Points
Damage to the occipital lobe can cause blindness and other visual distortions, including hallucinations.
Although living with visual problems can be difficult, occupational and speech therapists can help you adapt and make things a little easier. Vision therapy techniques might also help you improve the vision you still have.
Keep in mind that the brain is remarkably adaptive. With enough therapy, it can actually rewire nerve cells to allow undamaged brain regions to take over functions from damaged ones.
Which means even if you have severe occipital lobe damage, you might still regain your sight after brain injury. Good luck!