Scotoma (Blind Spot in Vision): Types, Causes, and Treatment

A scotoma is an abnormal blind spot in your field of vision: an area where you cannot see clearly, surrounded by normal sight. It can look like a dark spot, a blurry patch, or a shimmering arc of light, and it can affect the center or edges of your vision in one or both eyes. Scotomas are different from the small natural blind spot everyone has where the optic nerve enters the eye; an abnormal scotoma usually signals a problem with the retina, optic nerve, or brain. Common causes include migraines, glaucoma, macular degeneration, and diabetic retinopathy.

Scotomata is the plural of scotoma. Both terms refer to the same abnormal blind spots in the visual field. The word comes from the Greek skotos, meaning "darkness."

Quick Answers About Scotomas

What is a scotoma caused by?

Scotomas come from problems with the retina, the optic nerve, or the visual processing centers in the brain. The most common causes are migraines (which produce a temporary scintillating scotoma), glaucoma, age-related macular degeneration, diabetic retinopathy, and optic nerve disorders. Less commonly, stroke, multiple sclerosis, brain tumors, and high blood pressure during pregnancy can also cause scotomas.

Will a scotoma go away?

It depends on the cause. A scintillating scotoma from a migraine usually disappears within 5 to 60 minutes. Scotomas from treatable conditions like wet macular degeneration or diabetic macular edema often shrink or stabilize with anti-VEGF injections, laser, or steroid treatment. Scotomas from permanent damage anywhere along the visual system (the retina, the optic nerve, the visual pathways, or the visual cortex) are often permanent. Advanced glaucoma, optic atrophy, and stroke are the most common reasons.

Is there treatment for scotoma?

Yes. Treatment targets the underlying cause: anti-VEGF injections for wet AMD or diabetic macular edema, laser therapy for proliferative diabetic retinopathy, steroids for optic neuritis or giant cell arteritis, and surgery for retinal detachment or severe glaucoma. When vision loss is permanent, magnifying aids, prism glasses, and low-vision rehabilitation help you adapt.

Can stress cause scotomas?

Stress does not directly cause a scotoma, but it is a well-known migraine trigger, and migraines often produce scintillating scotomas. If you only see flickering arcs of light or jagged patterns during stressful periods or before a headache, the scotoma is likely migraine-related. New blind spots that appear without a headache need an eye exam to rule out other causes.

What is the meaning of scotomata?

Scotomata is the plural of scotoma; both terms refer to abnormal blind spots in the field of vision. The word comes from the Greek skotos, meaning "darkness." Scotoma is the more common spelling in modern medical writing.

What triggers a scotoma?

Common triggers and underlying causes include migraine (the most common trigger for a temporary scotoma), uncontrolled blood sugar in diabetes, raised eye pressure in glaucoma, certain medications (such as hydroxychloroquine, ethambutol, or vigabatrin), and high blood pressure during pregnancy. A sudden new scotoma after a head injury or with neurological symptoms is a medical emergency.

What is a scotoma in pregnancy?

A scotoma during pregnancy or shortly after delivery can be a warning sign of preeclampsia, a serious blood-pressure disorder. The classic picture is high blood pressure plus protein in the urine. But doctors also diagnose preeclampsia when new high blood pressure shows up with other warning signs: visual changes like scotomas, severe headache, or upper-abdominal pain. Any of these in pregnancy or just after delivery need same-day evaluation by your obstetrician or the labor-and-delivery ward, not your eye doctor.

What is the difference between a scotoma and a floater?

A scotoma is a fixed blind area in your field of vision; it stays in the same place when you move your eyes. A floater is a small mobile shadow cast by debris drifting inside the gel of the eye; it moves when you move your eyes and often drifts when you stop. Floaters are usually harmless. New scotomas are not.

What Are the Different Types of Scotomas?

Scotomas are grouped two ways: by location in the visual field (central, paracentral, peripheral, hemianopic) and by what you see (positive scotomas appear as a visible spot or shimmer; negative scotomas are an invisible gap you notice only when objects in it disappear).

Central Scotoma

A central scotoma sits directly in the middle of your vision. Macular degeneration, diabetic macular edema, optic neuritis, and toxic optic neuropathies are the usual causes. Reading is the first thing to suffer: letters drop out of the middle of the page, and many people learn to use eccentric viewing (looking slightly to the side of an object) to see around the spot. AMD is the leading cause of central scotomas in adults over 50.

Paracentral and Arcuate Scotomas

Paracentral scotomas sit near, but not in, the line of sight. Arcuate scotomas are a curved type of paracentral defect that follow the path of nerve fiber bundles in the retina. Both are classic findings in glaucoma, which damages those nerve fibers, usually (though not always) when eye pressure is elevated. Some people develop glaucoma at normal eye pressures.

Bjerrum (Arcuate) Scotoma

A Bjerrum scotoma is a specific arc-shaped defect that curves above or below the central fixation point, ending at the horizontal midline of vision. It is one of the earliest visual-field changes in glaucoma and is detected on a Humphrey visual field test.

Ring Scotoma

A ring scotoma is a band of vision loss that surrounds central vision, leaving both the very center and the far periphery intact. Advanced retinitis pigmentosa, certain drug toxicities, and advanced glaucoma produce ring-shaped defects.

Cecocentral Scotoma

A cecocentral scotoma stretches from the blind spot (the optic disc) toward the center of vision. It is a hallmark of toxic and nutritional optic neuropathies (from alcohol, methanol, vitamin B12 deficiency, or medications like ethambutol) and is also seen in Leber hereditary optic neuropathy.

Junctional Scotoma

A junctional scotoma is a paired pattern: a central scotoma in one eye and a temporal field defect in the other. It signals damage at the junction of the optic nerve and the optic chiasm, often from a pituitary tumor or other compressive lesion.

Hemianopic Scotoma

A hemianopic scotoma blanks out half the visual field: either the left half or right half in both eyes simultaneously. Stroke is the most common cause; brain tumors and traumatic brain injury can also produce the pattern. Sudden hemianopic vision loss is a medical emergency.

Scintillating Scotoma

A scintillating scotoma is the shimmering, flickering, often C-shaped arc of light that appears during migraine aura. Clinicians call the zigzag pattern a "fortification spectrum" because it resembles a bird's-eye view of a medieval fortress. It expands across the visual field over 5 to 60 minutes and then disappears, frequently followed by a headache. A typical recurrent pattern like this (gradual spread, 5 to 60 minutes, full recovery) is usually migraine-related and benign. Some patterns deserve a closer look and prompt medical evaluation: a first-ever episode, symptoms in only one eye, episodes shorter than 5 minutes or longer than an hour, new symptoms after age 50, or weakness or speech changes during the episode.

What Are the Symptoms of a Scotoma?

A scotoma stays in the same place when you move your eyes; this is the single most reliable way to tell it apart from a floater, which moves with eye movement. Beyond that, scotomas come in two flavors: positive (a visible spot or shimmer you can see) and negative (an invisible gap you notice only when objects in it seem to vanish).

Visual symptoms (what the scotoma looks like):

• A dark, gray, or fuzzy spot in your vision
• A blurry or distorted patch where details disappear
• An expanding zigzag arc of flashing light (a scintillating scotoma, often C-shaped)
• A missing area you only notice when objects in it seem to disappear (a negative scotoma)
• A blind area that stays put when you move your eyes

Functional symptoms (what the scotoma stops you from doing):

• Trouble reading, with words or letters dropping out of the middle of the page
• Difficulty recognizing faces or seeing colors clearly
• Bumping into objects or missing things in your peripheral vision (especially with arcuate or hemianopic scotomas)

Associated symptoms (what may come with the scotoma):

• Headache, especially with scintillating scotoma during migraine aura
• Light sensitivity, eye pain, or wider vision loss, which point to a treatable underlying condition

A negative scotoma is easy to overlook. The brain fills in the missing area with surrounding patterns, so many people notice the defect only when something in the blind area disappears: a car at an intersection, a word on a page, a person standing in a doorway. If a scotoma feels intermittent or hard to pin down, that is often why.

What Causes a Scotoma?

Scotomas form when one of three systems is damaged: the retina (macular degeneration, diabetic retinopathy, retinal detachment), the optic nerve (glaucoma, optic neuritis, toxic optic neuropathy), or the visual processing centers in the brain (stroke, tumor, occipital lesion). Migraine works by a different mechanism: a temporary wave of activity in the visual cortex that produces a scintillating scotoma without any structural damage.

Migraine:

• Migraine aura. A temporary scintillating scotoma from a wave of activity in the visual cortex, usually lasting 5 to 60 minutes. It resolves on its own and leaves no permanent visual-field defect.

Eye and retinal causes:

• Age-related macular degeneration (AMD). A gradual central scotoma as the macula deteriorates. Wet AMD progresses faster than dry AMD and is treated with anti-VEGF injections.
• Glaucoma. A paracentral or arcuate scotoma from optic nerve damage. It usually starts in peripheral vision and creeps inward.
• Diabetic retinopathy. A central or paracentral scotoma from high blood sugar damaging the retinal blood vessels.
• Retinal detachment. A sudden curtain or shadow over part of vision; a medical emergency.

Optic nerve causes:

• Ischemic optic neuropathy. A sudden scotoma when blood flow to the optic nerve drops, most often in people over 50 with cardiovascular risk factors.
• Optic neuritis. Inflammation of the optic nerve, often linked to multiple sclerosis, causing a central scotoma with eye pain on movement.
• Toxic and nutritional optic neuropathy. A central or cecocentral scotoma from alcohol, methanol, tobacco, or vitamin B12 deficiency.
• Optic atrophy. Permanent loss from optic nerve cell death. The scotoma it causes does not reverse.

Drug-induced causes:

• Toxic medications. Chloroquine and hydroxychloroquine (Plaquenil), ethambutol, vigabatrin, tamoxifen, and high-dose sildenafil have all been linked to retinal or optic-nerve toxicity. Stopping or switching the drug limits further damage in many cases, but recovery varies and some visual-field loss is permanent. Hydroxychloroquine and chloroquine damage in particular keeps progressing for months or years after the drug is stopped, which is why ophthalmologists screen long-term users.
• Sclerotherapy (rare). Transient visual disturbances have been reported after foam sclerotherapy for varicose veins, especially in people with a patent foramen ovale.

Can Scotomas Be a Sign of Something Serious?

Yes, and the underlying conditions range from migraine, which is benign, to stroke and preeclampsia, which are emergencies. Knowing the pattern helps you act on the right one:

• Multiple sclerosis (MS). A demyelinating disease that damages the optic nerve (optic neuritis), causing a central scotoma. High-dose steroids speed how quickly vision returns but do not usually change how well it recovers in the end; many people get most of their sight back either way.
• Stroke. A blockage or bleed in the visual pathway can produce a hemianopic or quadrantanopic scotoma: half or a quarter of the visual field disappears suddenly. Sudden vision loss in this pattern is a stroke until proven otherwise.
• Seizures. Occipital-lobe seizures can briefly produce a scintillating or geometric scotoma, sometimes mistaken for migraine aura.
• Hypertension. Uncontrolled high blood pressure damages retinal blood vessels (hypertensive retinopathy), producing scotomas and other vision changes.
• Preeclampsia. A serious pregnancy blood-pressure disorder. The classic version involves high blood pressure plus protein in the urine. Doctors also diagnose it when new high blood pressure shows up with other warning signs: visual changes like scotomas, severe headache, or upper-abdominal pain. New scotomas, flashing lights, or blurred vision during pregnancy or shortly after delivery need same-day obstetric evaluation, not just an eye exam.

When Should You See a Doctor?

Call 911 or go to the ER right away for sudden loss of vision, or sudden loss of half or a quarter of your visual field. Also call 911 for any new blind spot that comes with confusion, slurred speech, weakness, numbness, severe headache, or a head injury; these are stroke and neurological emergencies. Sudden flashes of light, a shower of new floaters, or a curtain-like shadow over your vision can mean a retinal detachment. Get same-day emergency eye care or go to the ER even without stroke symptoms. For any other new scotoma without those red flags, see your eye doctor the same day. Schedule a routine eye exam within 1 to 2 weeks for a scotoma that has been present for a while or changes slowly.

Emergency red flags (call 911 or go to the ER):

• Sudden loss of vision in one or both eyes
• Sudden loss of half or a quarter of the visual field
• Confusion or disorientation
• Dizziness or nausea
• Muscle weakness on one side of the body
• Sudden severe headache
• Numbness in your limbs or face
• Slurred speech or difficulty speaking
• A scotoma that follows a head or eye injury

If you are pregnant or recently gave birth and develop a scotoma with headache, upper-abdominal pain, or swelling, call your obstetrician or go to labor and delivery; these are preeclampsia warning signs.

How Are Scotomas Treated?

Scotomas are not treated directly; treatment targets the underlying cause. Medical treatments stop or reverse the damage; rehabilitation tools help you adapt when vision loss is permanent.

Medical Treatments

• Anti-VEGF injections. The first-line treatment for wet AMD and diabetic macular edema. Injections such as ranibizumab or aflibercept block abnormal blood vessel growth and reduce fluid leakage, stabilizing or improving central vision in most patients when started early.
• Laser therapy. Used for proliferative diabetic retinopathy. Laser treatment shrinks abnormal blood vessels and reduces leaking or swelling in the retina.
• Steroid treatment for optic neuritis. Intravenous corticosteroids speed the recovery of vision in typical optic neuritis, but they do not usually change the final outcome; most cases recover substantially even without treatment.
• Urgent steroids for giant cell arteritis. Suspected giant cell arteritis is a vision-saving emergency: high-dose steroids start immediately to prevent permanent blindness in the second eye.
• Surgery for retinal detachment. Surgical repair restores some vision when performed quickly, though the outcome depends on how long the retina was detached and whether the central macula was involved.
• Glaucoma surgery. Lowers eye pressure to preserve the vision you still have. It does not restore vision already lost to glaucoma.

Rehabilitation and Support

When vision loss is permanent, several tools and training programs help you stay independent:

• Magnifying aids. Handheld magnifiers, enlarged-print devices, and electronic readers for central vision loss.
• Prism glasses. Shift images out of the blind area, useful for some patients with peripheral vision loss or hemianopia.
• Low-vision rehabilitation. Teaches scanning strategies, eccentric viewing, and use of assistive devices like magnifiers and screen readers to improve daily function. Many programs also include orientation and mobility training, daily-living skills, and emotional support.
• Community support. Groups and resources from the Macular Degeneration Association, the Glaucoma Research Foundation, and state low-vision services provide emotional support and practical coping strategies.

Key Takeaways

• A scotoma is an abnormal blind spot, distinct from the small natural blind spot everyone has where the optic nerve enters the eye.
• Migraine is the most common cause of a temporary scotoma; glaucoma, AMD, and diabetic retinopathy are the most common causes of a permanent one.
• A new scotoma always warrants an eye exam. Sudden vision loss, or a new scotoma with neurological symptoms (slurred speech, weakness, sudden severe headache), is a 911-level emergency.
• Treatment depends on the cause; many scotomas can be stopped or reversed if caught early, and rehabilitation tools help you adapt when vision loss is permanent.