Scotoma: Understanding Blind Spots in Your Vision
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is a scotoma?
A scotoma is a blind spot, an area of the visual field where you temporarily or permanently see less well or not at all. It occurs when a problem in the retina, optic nerve or certain brain areas disrupts visual signals. Some scotomas, like those linked to migraine, are temporary, while others signal conditions such as glaucoma or stroke. [1]
What the research says
Macular degeneration, a leading cause of central scotomas, is very common. A systematic review and meta-analysis of 39 studies (129,664 people) estimated that 8.69% of people aged 45 to 85 have some form of age-related macular degeneration, including 0.37% with late disease. The authors projected 196 million people affected in 2020 and 288 million in 2040 (Wong et al., Lancet Glob Health, 2014). [2]
Migraine, a common cause of scintillating scotomas, is linked to a higher risk of bleeding stroke. A meta-analysis of 8 studies involving 1,600 hemorrhagic strokes found that people with any migraine had a pooled adjusted risk of 1.48 (95% CI 1.16 to 1.88) compared with people without migraine. For migraine with aura alone the result was not statistically significant (1.62, 95% CI 0.87 to 3.03) (Sacco et al., Stroke, 2013). [3]
What is a scotoma?
The word scotoma comes from the Greek word for darkness. The retina is the layer at the back of the eye that turns light into electrical signals, and the optic nerve sends those signals to the brain. A scotoma may be a spot on the retina where the nerves are not working and are not sending signals, or it can come from conditions that affect the optic nerve or certain areas of the brain. [1]
Everyone has a natural blind spot at the point where the optic nerve goes through the retina. It is usually not noticeable because your brain fills in the empty spot. The scotomas that matter medically are the ones you can notice or that testing reveals. [1]
Scotomas can be positive or negative. With a positive scotoma you see something, such as a spot of a particular color. With a negative scotoma you do not know you have a blind spot, and your provider finds it during testing. [1]
What are the types of scotomas?
Type | Description | Common Presentation |
|---|---|---|
Central | A blind spot in the middle of your vision. | A dark spot straight ahead, or an area where vision is not clear. |
Scintillating | A jagged or wavy disturbance that can shift from light to dark and back. | Often happens with migraine with aura and often does not last long. |
Paracentral | A blind spot within 10 degrees of fixation, slightly off to the side of where you look. | You may have more than one. |
Junctional | Caused by damage where the optic nerve meets the optic chiasm, near the base of the brain. | Complex visual field loss. |
What causes a scotoma, and who is at risk?
A scotoma is a sign of another problem rather than a disease on its own. Where the problem is located determines what the blind spot looks like. [1]
Location | Common Causes |
|---|---|
Retina | Age-related macular degeneration, retinal injuries including burns, retinal tears and detachment, and diabetes-related retinopathy. |
Optic nerve | Glaucoma, multiple sclerosis, and inflammation of the optic nerve. |
Brain | Stroke, traumatic brain injury, tumors (including pituitary tumors), and aneurysms. |
Systemic or other | Diabetes, high blood pressure, hormone changes, migraine, and medication side effects. |
For more on these conditions, see our guides to migraine headaches, stroke, retinal tear, optic neuritis, and multiple sclerosis.
Central scotomas: Often from macular degeneration, strokes, tumors, scars from eye injuries, or traumatic brain injury. [1]
Junctional scotomas: Often from pituitary tumors, other tumors such as craniopharyngioma, aneurysms, infections such as syphilis and tuberculosis, or demyelinating conditions such as multiple sclerosis. [1]
Paracentral scotomas: Often from glaucoma (which can cause an arc-shaped blind spot), diabetes-related retinopathy, or retinal tears and detachments. [1]
Scintillating scotomas: Often from migraine with aura (with or without pain), high blood pressure, hormone changes, or blood-clotting disorders. [1]
What are the symptoms of a scotoma?
Beyond a spot of blocked or disturbed vision, a scotoma may cause difficulty seeing certain colors, a need for bright light, and eye floaters and flashes. [1]
Difficulty seeing certain colors.
Needing bright light to see well.
Eye floaters and flashes of light.
How is a scotoma diagnosed?
Your provider will ask about your medical history and symptoms and may use the following tests. If they suspect a particular disease, you may also need blood tests or imaging to look for tumors. [1]
Eye exam: A painless exam that tests your vision and eye health. [1]
Visual field testing: Measures how far you can see in each direction without moving your eye and how sensitive your vision is in different parts of the visual field. [1]
Optical coherence tomography (OCT): A noninvasive imaging method that creates a picture of the back of your eye. [1]
How is a scotoma treated and managed?
Treatment means treating the condition that is causing the scotoma. This is especially true for glaucoma, macular degeneration, stroke, and cancer. [1]
Scotomas that need no treatment: Some, such as scintillating scotomas, may ease if you lie down to rest or drink water. [1]
Migraine-related scotomas: Your provider may suggest medicines ranging from over-the-counter pain relievers to triptans to anti-seizure medications. [1]
Chronic conditions: Controlling blood sugar in diabetes and blood pressure in hypertension helps protect the eyes. [1]
Surgery and procedures: Some causes, such as retinal tears or tumors, may need procedures to repair or remove them.
Low vision aids: For lasting vision loss, proper lighting, magnifiers, or equipment that reads to you can help. [1]
What is the outlook for a scotoma, and can it be prevented?
The outlook depends on the cause. Temporary scotomas go away once a migraine is over or blood pressure stabilizes. When a disorder is the cause, the scotoma might not disappear and might even get larger. A scotoma, especially a central one, can interfere with reading or driving, so ask your provider about low vision aids. [1]
There is no way to prevent a scotoma in every situation. Preventive medicines may prevent scotomas that come with migraines. If you have a condition linked to scotomas, get regular eye exams and aim for steady blood sugar if you have diabetes and well-managed blood pressure if you have hypertension. [1]
When should you get medical help for a scotoma?
Contact your healthcare provider about any change or worsening in your vision. [1]
Call 911 or go to the nearest emergency room if a scotoma comes with any of the following: [1]
A severe headache that starts suddenly.
Problems speaking.
Numbness in your limbs or face.
Nausea.
Flashes of light and floaters together with a shadow or dark spot. These can be signs of retinal detachment, which is often painless but is a medical emergency. [1]
Conclusion
A scotoma is a signal worth taking seriously. Some blind spots are temporary and harmless, such as those during a migraine aura, while others point to conditions that need prompt treatment. Finding the cause early is the best way to protect your sight.
What are the next steps if you have a scotoma?
If you notice a new blind spot, flickering lights, or a sudden change in your field of vision, schedule an eye exam right away. If you have diabetes, high blood pressure, or migraines, keep up with regular eye exams and manage those conditions as your provider advises.
Frequently Asked Questions
What causes a scotoma?
Many conditions, including migraine, macular degeneration, glaucoma, diabetes, multiple sclerosis, stroke, retinal injuries, tumors, and some medication side effects. A provider needs to find the cause to guide treatment. [1]
Can a scotoma go away on its own?
Some are temporary and go away once the migraine is over or blood pressure becomes stable. Scotomas caused by a disorder may not go away and can even grow larger. [1]
Is a scotoma always a dark spot?
No. It can look like a dark, blurry, or unclear area, a flickering jagged shape, or a spot of color. Some people do not notice it at all. [1]
How can a doctor find a blind spot I cannot see?
Visual field testing measures how sensitive your vision is in different parts of your visual field and can reveal a negative scotoma you are unaware of. [1]
Can stress cause a scotoma?
Stress can trigger migraines in some people, and migraine with aura can cause a scintillating scotoma. Stress is not a cause of every scotoma.
Is a scotoma a sign of stroke?
A scotoma can be. Stroke is one cause of scotomas. Get emergency care if a vision change comes with a sudden severe headache, trouble speaking, or numbness in your face or limbs. [1]
What is a scintillating scotoma?
A jagged or wavy visual disturbance that can shift from light to dark and back. It often happens with migraine with aura and often does not last long. [1]
Can diabetes lead to scotomas?
Yes. Diabetes-related retinopathy is a common cause of paracentral scotomas. [1]
Is everyone born with a scotoma?
Everyone has a natural blind spot where the optic nerve goes through the retina. It is usually unnoticeable because the brain fills in the gap. [1]
What is the difference between a positive and a negative scotoma?
With a positive scotoma you see something, such as a spot of color. With a negative scotoma you do not know the blind spot is there until it is found in testing. [1]
Can eye injuries cause blind spots?
Yes. Retinal injuries, including burns, and scars from eye injuries can cause scotomas, including central scotomas. [1]
Does glaucoma cause scotomas?
Yes. Glaucoma can cause an arc-shaped (arcuate) paracentral scotoma. [1]
Can medications cause blind spots?
Medication side effects are one possible cause. Tell your provider about every medicine you take. [1]
What should I do if I see sudden flashes of light?
Flashes and floaters together with a shadow or dark spot can signal retinal detachment, which is a medical emergency even though it is often painless. Seek care immediately. [1]
Do vitamins help a scotoma?
Treatment depends on the cause, and supplements do not fix a scotoma on their own. Ask your provider before starting any supplement.
Related Reading
Visual Field Test: Types, What to Expect and What Results Mean explains the test that maps your side vision.
References
Cleveland Clinic. Scotoma. Cleveland Clinic. January 18, 2023. https://my.clevelandclinic.org/health/diseases/24687-scotoma
Wong WL, Su X, Li X, et al. Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis. Lancet Glob Health. 2014;2(2):e106-e116. PMID 25104651. https://doi.org/10.1016/S2214-109X(13)70145-1
Sacco S, Ornello R, Ripa P, et al. Migraine and hemorrhagic stroke: a meta-analysis. Stroke. 2013;44(11):3032-3038. PMID 24085027. https://doi.org/10.1161/STROKEAHA.113.002465
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the guidance of a qualified healthcare provider regarding any vision changes or medical conditions. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.
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