Palinopsia can feel like an optical illusion when first experiencing it. However, rather than manufactured visual images that trigger an optical illusion, palinopsia occurs when the eye-brain connection causes an image to linger or leave a trail, even when it’s out of the field of vision.
Symptoms Of Pallinopsia
The word palinopsia is rooted in Greek and means “repeated view.” There are two types of palinopsia: illusory and hallucinatory.
Illusory palinopsia
An illusion happens when your eyes look at one thing, but the brain thinks it’s another. For example, you might think you saw a turtle – and then realize it’s a rock. Or you might see a bear, where really there’s just a large shrub.
With illusory palinopsia, patients may see an object as if it’s leaving a long, bright tail behind it – sort of like a comet. Or, a dog might cross their path, but they still see a “trail of dogs” trailing behind it – although only one dog is present. However, these images are not as solid or clear as the original. Instead, they are less distinct and have a low resolution.
Sometimes, these illusory images are broken into fragments or occur continuously. However, regardless of how a patient sees them, they are always triggered by something that actually appeared in the field of vision right beforehand (in other words, they are not hallucinations).
Hallucinatory palinopsia
We typically think of hallucinatory events as a trick of the brain or the result of a mental illness or recreational drug side effect. Hallucinatory palinopsia is not a truly hallucinatory event in those terms, but it does involve a person continuing to see a blurred or suspended image after the image is completely gone. Instead of being indistinct or low-resolution, the repeating or recurring images look just as solid and clear as they originally appeared.
In this case, the image is completely removed from the person’s field of vision, but they continue to see it. Sometimes, hallucinatory palinopsia occurs with simple visual stimuli, like colors or shapes. However, it can also be more complicated, like an action scene replayed right before you. Or, like a superimposed picture, you might see something that happened overlaid onto the current frame.
Most of the time, individuals only experience hallucinatory palinopsia in short bursts or in a very short period. The images don’t linger for more than a few seconds at most. However, some people experience long-term hallucinatory palinopsia, where images linger or replay for multiple moments or even hours.
Types Of Afterimages
These suspended images are called “afterimages,” and there are two different types:
Positive afterimages
People who experience positive after-images see the image as it appeared originally in terms of color. If a girl was wearing a red shirt and blue pants, you’d see an afterimage of the girl in a red shirt and blue pants.
Negative afterimages
Negative afterimages appear in reverse. This happens commonly to all of us after a bright flash goes off. Afterward, a dark spot the same size and burst of the flash appears in your field of vision.
What Causes Palinopsia?
Most of the time, patients experiencing episodes of palinopsia have something amiss with their neurotransmitters (called the chemical messengers). There are several potential causes for palinopsia:
Migraines
About 10% of people who experience migraines experience illusory palinopsia, particularly if their migraines involve an aura (a visual onset of the extreme headache).
Side effects of recreational drugs or prescription medications
People who take mind-altering recreational drugs often experience some level of palinopsia. Drugs as mild as marijuana (THC) can cause illusory palinopsia. We’re hearing about this more and more from patients who vape since those chemicals are far stronger than the typical joint.
Psychedelics, including psilocybin, LSD, mescaline, and DMT can cause both illusory and hallucinatory palinopsia. The latter can be detrimental if the person under the influence can’t discern the false images caused by the drug.
Some prescription medications used to treat diseases or medical conditions can cause palinopsia. For example, women taking the popular fertility medication Clomiphene citrate (Clomid) have experienced it to varying degrees. Blurred vision is a common medication side effect of the drug, so they know why it’s happening and should check in with their fertility specialist.
In most cases, drug or medication-induced palinopsia ceases immediately after patients stop taking the medications. However, there are some cases where the phenomena become permanent.
Head trauma or other issues in the brain
Any injury to the head can interfere with how the brain processes images. In some cases, a severe head injury may cause temporary or permanent palinopsia.
However, other issues in the brain can interfere with visual processing and cause illusory or hallucinatory palinopsia. These include:
- Small hemorrhages.
- Abscesses.
- Atrophy aneurysms.
These are all considered types of brain lesions and are typically detected via an MRI if an optometrist or ophthalmologist can’t determine the cause of the symptoms.
Metabolic imbalances that cause seizures
Sometimes, patients experience seizures that include episodes of paliopsia. These may be caused by metabolic imbalances such as carnitine deficiency, severe hyperglycemia, or ion channel disturbances.
Diagnosing & Treating Palinopsia
In most cases, diagnosing palinopsia is a multi-step process. Disease- or medication-related episodes may be easier to get to the bottom of as the risks are already known. However, sudden palinopsia with no apparent causes may require a combination of visits to:
- Your general physician.
- Optometrist/ophthalmologist.
- Neurologist.
These physicians will use a combination of tools to diagnose the cause, including a complete medical history, a physical, visual field testing, or an MRI to provide images of the brain and spine.
Treatment always relates direction to the cause. For example, migraine-related issues can be eliminated or reduced by managing migraines with the right lifestyle changes and medications. The same is true for palinopsia related to other medical conditions.
Medication-related palinopsia may require a change in medications if possible. In some cases, special sunglasses or contact lenses may reduce the effects of palinopsia.
Schedule An Appointment ASAP If You Experience Palinopsia
Schedule an appointment with the Atlantic Eye Insitute immediately if you’re experiencing episodes and palinopsia with no apparent cause. This is not something that should be overlooked or ignored. In addition to posing a safety risk when out in public, extended periods of palinopsia can cause anxiety and depression because of the way it inhibits daily life. We’re here to get to the root cause and support you however we can.