Occipital Lobe

What is the occipital lobe?

The occipital lobe is a part of your brain located at the back of your head. Though it’s the smallest lobe of your brain, it’s still extremely important. That’s because the occipital lobe processes visual signals sent from your eyes.

What does the occipital lobe do?

The pupils of your eyes are like windows, allowing light from the world in front of them to enter your eye. Inside, at the back of each eye, is a patch of incredibly sophisticated cells known as the retina. Your retinal cells take what you see and turn those images into a kind of highly detailed coded message.

The coded messages travel along your optic nerves toward your brain and then travel within your brain optic tracts. Along the optic tracts, areas of your brain, like the thalamus, relay the coded signals until they reach your occipital lobe. The main job of your occipital lobe is decoding the messages sent from your eyes and turning that information into forms the rest of your brain can use.

That job happens in two specific areas in your occipital lobe: the primary visual cortex and the secondary visual cortex. The term “cortex” comes from the Latin word for “tree bark,” and it describes the wrinkly-textured outer surface of your brain. The visual cortices (the plural of “cortex”) are parts of the cortex that process vision-related signals.

Everything your eyes can do falls under the term “vision,” but that actually involves several different processes and capabilities. Those include:

• Spatial (pronounced “spay-shul”) processing: This is your brain’s decoding of signals from your retinas. It’s how you see the shapes, textures and other details of the objects in the world around you.
• Color processing: This helps you see and tell the difference between colors and all the different shades of them (unless your eyes can’t see certain colors, such as with certain types of color blindness).
• Distance and depth perception: This is when your brain calculates the size of objects and the distance between you and what you see.
• Object and face recognition: This is your brain’s ability to recognize things you’ve seen before, including the faces of people you’ve seen or met.

How does the occipital lobe help other organs or body systems?

Your eyes detect what’s visible in the world around you and turn that information into signals that then travel to your brain. However, the occipital lobe is what takes those signals, processes them and then works cooperatively with other parts of your brain to use what you see.

One of the most important examples of this is reading. Your occipital lobe recognizes writing, and then it works with a part of your brain’s temporal lobe to recognize the written shapes and symbols. The temporal lobe then understands them as written language and processes the content.

Where is the occipital lobe located?

Your occipital lobe is at the very back of your skull. It’s just inside your skull, right above the hollow at the back of your head. Like all lobes of your brain, your occipital lobe has a left and right side, with a groove dividing it into the left and right sides.

How big is the occipital lobe and how much does it weigh?

Your occipital lobe is the smallest of the lobes of your brain. The average occipital lobe makes up between 10% and 18% of your brain’s volume (there’s uncertainty because experts disagree on exactly the exact borders that separate the lobes from their neighbors).

What is the occipital lobe made of?

Your occipital lobe is made up of the same cells that make up every other area of your brain. The basic cell types include:

• Neurons: These are the cells in your brain and nerves that can send or relay signals to other neurons. The signals travel as electricity, or “impulses” inside your neurons. Your neurons convert the electrical signals into chemicals that are released outside of the neuron. The next neuron detects the chemicals and triggers another impulse. In this way, a message travels quickly within and across neurons.
• Glial cells: These are your nervous system’s support cells. They don’t manage signals. Instead, they maintain the neurons by clearing waste matter, providing nutrients and offering structural support.

What does the occipital lobe do in people who have blindness?

For those who have blindness, their occipital lobe is still active. The type of activity in that lobe depends on if a person was born with blindness or developed it very early in life, or if they developed it later on.

Occipital lobe activity in those blind from birth or early in life

In those with early or congenital blindness, their occipital lobe is still very active. However, that activity happens when they use their other senses, such as smell, hearing and touch. The occipital lobe of a person with blindness also becomes more active when they’re speaking or listening to others talking.

This reassignment of the occipital lobe is a form of neuroplasticity. That’s the term for the brain’s ability to adapt itself to an unusual circumstance or condition.

Occipital lobe activity in those who developed blindness later in life

People who develop eye-based blindness later in life have a visual cortex that once handled visual information. While it may no longer receive as much (or any) vision-based input, it still responds similarly to input from other senses.

Two key ways this happens are with the senses of hearing or touch. In effect, your brain redirects its visual processing abilities to other senses. That allows a person to “see” an object by feeling it, or to form a mental image of their surroundings based on what they can hear.

What common conditions and disorders affect the occipital lobe?

Any condition that can affect your brain tissue can affect your occipital lobe. Examples include:

• Alice in Wonderland syndrome.
• Uncommon types of Alzheimer’s disease, such as posterior cortical atrophy.
• Brain lesions (from either diseases or damage from surgery or medical procedures).
• Brain tumors (including cancer).
• Carbon monoxide poisoning.
• Concussions and other traumatic brain injuries.
• Heavy metal poisoning or other toxins.
• Infections (including those that cause encephalitis).
• Lewy body dementia.
• Migraines.
• Posterior reversible encephalopathy syndrome (PRES).
• Seizure-related conditions, such as epilepsy.
• Stroke.
• Visual agnosias (this term can also refer to symptoms rather than conditions).

What are some common signs or symptoms of occipital lobe conditions?

Because your occipital lobe’s jobs all revolve around your vision, the symptoms of conditions that affect it are all vision-related. Examples of these symptoms (with more about them below) include:

• Vision loss (either partial or total).
• Visual anosognosia (Anton syndrome).
• Visual agnosias.
• Visual illusions (such as distortions that happen with migraine auras).
• Visual hallucinations.

Vision loss

Damage to your occipital lobe can cause you to lose part or all of your field of vision. It can affect one eye at a time or both eyes. When loss is total and affects both eyes, it’s known as cortical (cortex-related) blindness. If you have this, your brain can’t process vision-related nerve signals — even though your eyes are working correctly — causing you to experience blindness.

Visual anosognosia (Anton syndrome)

Damage to your brain can disrupt your brain’s self-monitoring processes, preventing you from recognizing symptoms or other signs of a problem. The most common form of visual anosognosia is when a person who has blindness denies that they have a vision issue. A rarer form of Anton syndrome is when a person believes they’re blind but shows signs that their vision still works (at least on an unconscious level).

Visual agnosias

These are when your brain can’t properly process what you see. The effect is similar to trying to open a file on your computer, but not having the right program to do so. Your computer can’t open it because it doesn’t know how to use the file. Likewise, visual agnosias mean your brain can’t process what your eyes see. However, other senses can sometimes help you compensate for this.

Examples of this include:

• Object agnosia: This is the ability to see an object, but not recognize it. You may still recognize it by sound (such as identifying a cat by its meow instead of by seeing it) or by touch (such as recognizing a key by feeling its shape instead of seeing it).
• Color agnosia: This type of agnosia can happen in a couple of ways. The first is losing the ability to process colors you see, making colors dimmer or making everything look gray (achromatopsia). The other main way it can happen is losing the ability to connect colors with their names. You can still see colors, but your brain can’t name them or recognize them by name alone. Color agnosia isn’t the same as color blindness, which is an eye disorder.
• Visual simultanagnosia: This is being able to see individual objects, but not understand how they relate to each other. An example of this is seeing individual trees clustered together in great numbers, but not being able to understand that what you’re seeing is a forest.

Visual illusions

These are when there are distortions or changes in your vision that happen because your brain isn’t processing signals from your eyes correctly. That can affect any of the following characteristics of what you see:

• Size: Objects may look larger or smaller than they should.
• Form: Objects take on a distorted appearance (think of how your reflection looks on a surface that isn’t flat, such as a wavy mirror or on the surface of moving water).
• Movement: Objects appear to move when it’s actually still, or vice versa.

Visual hallucinations

Under ordinary circumstances, a person’s vision happens because their brain is processing signals sent by their eyes. Once the signals reach your occipital lobe, neurons in that part of your brain send and relay signals to other areas in your brain. Visual hallucinations are when neurons in the occipital lobe act as if they’re processing signals from your eyes, but in reality, they’re acting on their own without such signals.

What are some common tests to check the health of the occipital lobe?

There are many ways that healthcare providers can check the health of your occipital lobe. These include diagnostic tests, lab tests, imaging scans and more. Examples include:

• Blood tests (these can detect many problems, ranging from immune system problems to toxins and poisons, especially metals like copper, mercury or lead).
• Computed tomography (CT) scan.
• Electroencephalogram (EEG).
• Electromyogram (nerve conduction test).
• Evoked potentials (sensory tests).
• Magnetic resonance imaging (MRI).
• Neuropsychological testing.
• Positron emission tomography (PET) scan.

What are common treatments for conditions affecting the occipital lobe?

Many conditions can affect your brain tissue, and the treatments for those conditions can vary widely. Treatments that work for one condition may not affect other conditions or might make other conditions much worse. A healthcare provider is the best person to tell you about available treatments for any brain-related condition. They’ll evaluate your medical history, circumstances, preferences and other factors to provide relevant answers for your situation.

What can I do to take care of my occipital lobe?

There are many things you can do to maintain the health of your entire brain, including your occipital lobe. Some brain-related conditions are preventable. Others may not be, but you might be able to reduce the risk of them happening. Some of the most important things you can do include:

• Eat a balanced diet: Vitamin levels that are too high or too low can cause problems with your brain, including your occipital lobe. Your diet also affects your circulatory health, which is vital for your brain to work correctly (a stroke is an example of a condition that happens when circulatory disorders affect your brain).
• Stay physically active and maintain a healthy weight: Your weight and activity level can prevent or delay conditions that affect your brain, especially circulatory problems like high blood pressure. A primary care provider can tell you what your ideal weight should be and help you find ways to reach and maintain that weight. Physical activity is also good for your brain, promoting not only good circulation, but also your brain’s natural production of helpful chemicals known as neurotransmitters.
• Wear safety equipment as needed: Head injuries, especially concussions and traumatic brain injuries, are particularly hazardous for your occipital lobe. That’s because this part of your brain is at the very back of your head, a location that’s particularly vulnerable to injury. Helmets, safety restraints (such as seat belts) and other types of protective gear can make a huge difference in preventing occipital lobe issues.
• Manage your chronic conditions: Many of the conditions that affect your brain worsen over time. However, treating those conditions can sometimes stop them or delay how long it takes for them to worsen. Examples of conditions like this include Type 2 diabetes, epilepsy and more.

A note from Cleveland Clinic

Your occipital lobe is the smallest lobe of your brain, but it’s one that most people rely on heavily. This part of your brain, found at the back of your head, processes signals from your eyes. Many conditions and disorders can affect it, but scientific and medical understanding of this brain area offers hope for diagnosing and treating many of these concerns.

Your occipital lobe also connects with many other parts of your brain, linking vision to many other abilities. It’s a key part of sensing and perceiving the world around you, and it sends information about your experience to different parts of your brain to form memories. Even though the occipital lobe is at the back of everyone’s mind — literally and figuratively — this part of your brain is one of the most important contributors to your everyday life.