When you’re sure you’ve seen something, then realize it’s not actually there, it can jolt you. It’s called a visual hallucination, and it can seem like your mind is playing tricks on you.
Beyond being scary or stressful, it’s also usually a sign that something else is going on. So if it’s happening to you, talk to your doctor. That’s the first step toward getting better.
Why It Might Happen
Alcohol and illegal drugs. Heavy drinking and certain street drugs, like ecstasy, cocaine, and LSD, can cause you to see anything from flashes of light to people. They can have the same effect when you quit after having used them for a long time.
Alzheimer’s disease and other kinds of dementia. In the late stages of Alzheimer’s, changes to the brain can lead to hallucinations. In another brain condition called Lewy body dementia, you may see complete scenes play out before your eyes.
Anton’s syndrome. This is a rare condition where you go blind but won’t admit it. Often, the people around you don’t know it’s happened until you run into something and make up some far-out reasons to explain why.
Brain tumors. Not everyone who has a brain tumor has visual hallucinations. But if the tumor presses on a part of the brain that handles vision, there’s a chance it could happen. If it does, you tend to see very lifelike scenes.
Charles Bonnet syndrome. This usually affects older adults who have serious eyesight problems, such as macular degeneration, cataracts, or glaucoma. In some cases, you see rich scenes filled with people and animals.
Delirium. Some drugs, infections, and other medical issues can bring on delirium, a condition where you’re confused and can’t focus or think clearly. It can seem a lot like a mental illness.
Epilepsy. What you might see with epilepsy depends on which part of your brain the seizures come from. Often, you’d see simpler images, like brightly colored spots or flashing shapes, but it could be more complex, too.
Intense stress. Daily, run-of-the-mill worries aren’t an issue. But more serious stress and other strong emotions can have a big impact. One common example is how people think they see a loved one after that person’s recent death.
Mental illness. Hallucinations are common with schizophrenia. Usually, you hear voices, but in more serious cases, you might see vivid scenes with family members, animals, or religious figures.
Seeing things isn’t as common in other mental illnesses, but it can sometimes happen with:
Migraines. About 1 in 3 people with migraines also get auras. They often come on as a flickering that grows into a crescent or C-shape with a zig-zag edge.
Parkinson’s disease. About half the people with Parkinson’s disease have hallucinations. Most of the time, these visions aren’t threatening. It may be more like watching a movie as you see a person off doing something in another part of the room.
Side effects from medicine. This is usually due to the dose and most often affects older adults. It’s more likely to happen if you take several kinds of medications.
Sleep issues. Seeing things just as you fall asleep or wake up is common and usually nothing to worry about. You might see a moving object or a person, but it seems a little dreamy. It’s more likely to happen if you tend to fall asleep randomly (narcolepsy) or have a hard time sleeping (insomnia).
Thyroid disease. Myxedema is a rare condition where your thyroid doesn’t make nearly enough hormone and the levels get dangerously low. This can cause several problems, from seeing things to falling into a coma.
First, you’ll get a physical exam and talk about your health history and symptoms. Your doctor might ask questions like:
- What exactly are you seeing?
- When did it start?
- Does it tend to happen at certain times, like as you’re falling asleep?
- Do you have any other symptoms when it happens?
- Is what you’re seeing scary? Threatening? Pleasant?
This usually gives your doctor clear clues about what other tests you should get. For example, you might need to see a psychiatrist to check for a mental illness. Your doctor may also order certain blood tests. And you might get an:
- Electroencephalogram (EEG), which measures electrical signals in your brain, to look for signs of epilepsy
- Eye exam to check for vision problems
- MRI to look for a brain tumor
It all comes down to your symptoms and where that points you.
The care you need depends on the condition that’s triggering your hallucinations. In many cases, if you can treat that, you’ll stop seeing things.
For example, it might be a quick fix where your doctor just needs to change the dose of a medicine or try a different drug. For something like a brain tumor, you might get chemotherapy, radiation, or surgery. With a mental illness like schizophrenia, you might need a mix of medicine, therapy, and other care.