A black spot in your vision can be anything from a harmless floater drifting across your line of sight to an early sign of a condition that needs urgent treatment. The most common cause by far is a change in the gel-like substance inside your eye, but the same symptom can also signal retinal tears, macular disease, vascular problems, and a handful of other conditions. What matters most is the pattern: a single translucent speck that moves when you shift your gaze is a very different situation from a fixed dark patch that stays in one place or a curtain-like shadow creeping across your peripheral vision.
Floaters and the Vitreous Gel
The inside of your eye is filled with a clear, jelly-like substance called the vitreous. Over time, tiny fibers within that gel clump together and cast shadows on the retina, which you perceive as spots, threads, or cobweb-like shapes drifting through your field of view. These are floaters, and most people notice them at some point, especially after middle age. They tend to be more visible against bright backgrounds like a white wall or a blue sky, and they drift when you move your eyes.
As you get older, the vitreous gel shrinks and eventually pulls away from the retina in an event called a posterior vitreous detachment (PVD). This is extremely common and, by itself, usually harmless. PVD can cause a sudden increase in floaters along with brief flashes of light, which can be alarming even though the process is benign in most people.1PubMed Central. Spontaneous posterior vitreous detachment: A glance at the current literature The flashes happen because the vitreous tugs on the retina as it separates, stimulating the light-sensitive cells mechanically rather than with actual light.
For most people who develop floaters from a PVD, the brain learns to tune them out over weeks or months. They do not disappear entirely, but they become far less noticeable. The concern is not the PVD itself but what it can occasionally trigger, which is the next topic worth understanding.
Retinal Tears and Detachment
When the vitreous pulls away from the retina, it sometimes tugs hard enough to tear a small hole in the retinal tissue. Among people who show up at an eye doctor’s office with sudden new floaters or flashes, roughly one in seven turns out to have a retinal tear.2JAMA. Acute-Onset Floaters and Flashes: Is This Patient at Risk for Retinal Detachment? That number is high enough to take seriously. If fluid seeps through the tear and gets behind the retina, it can lift the retina away from the supportive tissue underneath, causing a retinal detachment. Patients often describe this as a dark curtain or shadow spreading across part of their vision.3PubMed Central. Rhegmatogenous retinal detachment–an ophthalmologic emergency
A retinal tear caught early can usually be sealed with a quick laser or freezing procedure in an office setting. Once a full detachment develops, the situation becomes a surgical emergency. Delays in treatment increase the risk of permanent vision loss, so the classic warning combination of sudden new floaters plus flashes plus any shadow in your peripheral vision should prompt a same-day eye exam whenever possible.
Fixed Dark Spots and Macular Disease
Floaters drift. A dark spot that stays fixed in the center of your vision, so that it moves with your gaze and always blocks the same part of whatever you’re looking at, points toward a problem in the macula, the small area of the retina responsible for sharp central vision. Age-related macular degeneration is the most common culprit in older adults. As the macula deteriorates, a blind or dim patch called a scotoma can develop in your central field.
What makes macular scotomas tricky is that many people do not realize they have one. In a study of patients with age-related macular degeneration, binocular scotomas were present in about 88% of participants, yet more than half of those affected were completely unaware of the defect, even when the blind area measured up to 30 degrees across. There was no clear link between awareness and scotoma size, density, or visual acuity.4LWW / PubMed Central. Patient awareness of binocular central scotoma in age-related macular degeneration The brain is remarkably good at filling in the missing piece using information from the other eye or even from surrounding regions of the same eye, so you can walk around with a sizable blind zone and never notice it until a routine exam reveals it. Some patients reported that objects would seem to “disappear” occasionally, but they did not connect that experience to a permanent gap in their vision.
This is one reason eye doctors emphasize regular dilated exams after age 50, even when your vision feels fine. Early macular degeneration can sometimes be slowed with treatment, but only if it is caught before significant damage accumulates.
Macular Holes
A macular hole is a different kind of central-vision problem. Rather than degeneration across a broad area, a small full-thickness break develops in the center of the macula. This creates a focused dark or blurry spot right in the middle of your sight, often in just one eye. It can distort straight lines and make reading difficult.
Smaller lesions at the very center of the fovea, sometimes called foveal microholes, have been documented at sizes ranging from about 50 to 150 microns. In a case series, the condition appeared equally in men and women, with an average age around 40, and in most cases only one eye was involved. These microholes came on gradually without a history of trauma or sun exposure, and they tended not to progress.5PubMed Central. Microholes of the fovea centralis Larger macular holes, by contrast, often do require surgery (a vitrectomy) to close the hole and prevent further vision loss.
Vascular Causes
Blood supply problems can also produce dark spots or temporary blackouts in one eye. Amaurosis fugax, a term for transient monocular blindness, is typically caused by reduced blood flow through the carotid artery or a brief blockage of a retinal artery. A small clot or piece of plaque temporarily cuts off circulation, causing vision in one eye to go dark or gray for seconds to minutes before returning. The experience is often described as a shade being pulled down over the eye.6PubMed Central. Transient blindness
Even though the vision usually comes back, this is not a benign event. Transient monocular blindness can be an early warning of stroke. The underlying cause may be atherosclerosis in the carotid arteries, inflammation of blood vessel walls, or emboli originating from the heart. Anyone who experiences a sudden, painless blackout in one eye, even if it resolves within minutes, should treat it as an emergency and seek medical evaluation promptly.
A related scenario is a central retinal vein occlusion, where a clot blocks the vein draining blood from the retina. This tends to cause a more persistent dark spot or blurriness rather than a fleeting episode, and it often comes with swelling in the retina that an eye doctor can see during an exam. Risk factors overlap with those for heart disease and stroke: high blood pressure, diabetes, and smoking.
Inflammation Inside the Eye
Uveitis, an umbrella term for inflammation affecting the middle layers of the eye, can produce dark spots, haziness, and floater-like symptoms. When inflammation involves the back of the eye (posterior uveitis) or the vitreous cavity (intermediate uveitis), inflammatory cells accumulate in the gel and scatter light, creating visible spots or a generalized cloudiness. Imaging can reveal these cells as numerous punctate spots throughout the vitreous and retina.7Delhi Journal of Ophthalmology. Vitreous Punctate Spots in Eyes with Intermediate and Posterior Uveitis Using Spectral Domain Optical Coherence Tomography
Uveitis can stem from autoimmune conditions, infections, or sometimes no identifiable cause at all. The visual symptoms tend to improve as the inflammation is treated, but untreated or recurring episodes can damage the retina permanently. If you notice new floaters along with eye pain, redness, or light sensitivity, uveitis should be on the list of possibilities your doctor considers.
Solar and Photic Injury
Staring at the sun, even briefly during an eclipse, can burn the macula and create a persistent dark or discolored spot in your central vision. Solar retinopathy does not require prolonged exposure. In a case series of four young patients who watched a solar eclipse without proper eye protection, all developed macular damage visible on imaging. Three of the four showed reversible changes on follow-up, but one was left with visual acuity of roughly 6/24, a meaningful permanent loss.8PubMed Central. Acute eclipse retinopathy: a small case series
The damage from photic injury happens at the level of the retinal pigment epithelium and photoreceptor cells. There is no reliable treatment to reverse it once it occurs, which is why the emphasis is entirely on prevention. Eclipse glasses, welding filters rated for direct solar viewing, and indirect viewing methods are the only safe options. Regular sunglasses, even dark ones, do not block enough of the harmful wavelengths.
Medications That Affect Your Vision
Certain prescription drugs can cause scotomas or dark patches in your visual field as a side effect, sometimes after months or years of use. Two of the most well-known are hydroxychloroquine, widely prescribed for autoimmune conditions like lupus and rheumatoid arthritis, and amiodarone, used for heart rhythm disorders. Hydroxychloroquine can cause a distinctive pattern of macular damage called bull’s-eye maculopathy, while amiodarone can lead to optic neuropathy. Current guidelines recommend regular eye screening for patients on either medication to catch problems before they become irreversible.9PubMed. Ocular adverse effects associated with systemic medications: recognition and management
If you take either of these drugs and notice a new persistent dark spot or any change in your central vision, bring it up with your prescriber and your eye doctor. The damage from hydroxychloroquine can continue to progress even after the drug is stopped, so early detection matters. Other medications can also cause visual side effects, including certain cancer drugs and high-dose corticosteroids, but hydroxychloroquine and amiodarone are the ones most consistently linked to scotoma-like changes in the visual field.
Choroidal Nevi and the Risk of Melanoma
A choroidal nevus is essentially a freckle inside your eye, a flat, pigmented spot on the choroid, the blood-vessel-rich layer beneath the retina. Most choroidal nevi are found incidentally during routine eye exams and never cause symptoms. When a nevus sits near the fovea, though, it can cause a dark spot or mild distortion in central vision.
The worry with any choroidal nevus is the small but real chance that it transforms into choroidal melanoma, a malignant tumor. A large longitudinal analysis of over 2,300 cases identified a set of clinical features that raise concern: tumor thickness greater than 2 mm, the presence of fluid beneath the retina, vision loss to 20/50 or worse, orange pigment visible on imaging, a characteristic “hollow” pattern on ultrasound, and a diameter greater than 5 mm.10PubMed. Understanding choroidal nevus risk factors for transformation into melanoma If your eye doctor finds a nevus, they will typically photograph it and schedule periodic check-ups to watch for any of these changes. Most nevi stay benign indefinitely, but the monitoring is important because early-stage melanoma inside the eye is far more treatable than advanced disease.
When to Get Checked Urgently
Not every floater or momentary visual quirk needs an emergency visit, but certain patterns should send you to an eye doctor the same day or to an emergency room if a same-day appointment is not available:
- Sudden shower of floaters: A burst of many new floaters at once, especially tiny dark dots, suggests something is happening inside the vitreous that may involve the retina.
- Flashes of light: Particularly in one eye, repeated flashes suggest the vitreous is pulling on the retina. Combined with new floaters, this raises the probability of a retinal tear.
- A shadow or curtain: Any dark veil creeping across part of your vision is a hallmark of retinal detachment and warrants immediate evaluation.
- Sudden loss of vision: If part or all of your vision in one eye goes dark, even temporarily, the cause could be vascular and potentially related to stroke risk.
- Distorted central vision: Straight lines appearing wavy, or a new fixed dark patch in the center of your sight, can indicate macular disease or a macular hole.
Among patients with acute-onset floaters and flashes who see an ophthalmologist, reduced vision is the strongest predictor of a retinal tear. Even after an initial exam shows only an uncomplicated PVD, there is still roughly a 3-4% chance a retinal tear will develop over the following six weeks, and risk jumps sharply if new symptoms appear during that window, particularly the sudden onset of ten or more new floaters or any drop in visual clarity.2JAMA. Acute-Onset Floaters and Flashes: Is This Patient at Risk for Retinal Detachment? This is why eye doctors typically schedule a follow-up exam a few weeks after the initial evaluation, even when nothing alarming was found on the first visit.
Treating Bothersome Floaters
For the large majority of people whose dark spots turn out to be ordinary floaters, the standard advice has long been reassurance and patience. The brain adapts, and the floaters become less intrusive over time. But for a minority of patients, floaters remain disabling, interfering with reading, driving, or quality of life.
Two procedural options exist. Vitrectomy, a surgical procedure that removes the vitreous gel entirely and replaces it with saline, is effective at eliminating floaters but carries the risks of any intraocular surgery, including cataract formation and a small risk of retinal detachment. Laser vitreolysis uses short pulses of laser energy to break apart or vaporize floater clumps. A Cochrane review attempted to compare these two approaches but found no clinical trials that met its quality criteria, meaning there is currently no high-quality comparative evidence to guide the choice between them.11Cochrane Database of Systematic Reviews. Laser therapy versus vitrectomy for vitreous floaters
On the non-surgical side, a small body of research has looked at oral enzyme supplements as a way to dissolve vitreous opacities. One study tested a mixed fruit enzyme supplement at varying doses and found that floater disappearance rates ranged from about 55% to 70% over the course of the trial, with a dose-dependent pattern.12PubMed Central. A New Pharmacological Vitreolysis through the Supplement of Mixed Fruit Enzymes for Patients with Ocular Floaters or Vitreous Hemorrhage-Induced Floaters Those are intriguing numbers, but the evidence base is still thin, and these results have not been replicated in large independent trials. If you’re considering supplements for floaters, treat the marketing claims cautiously and talk to your eye doctor first.
The Difference Between One Eye and Both
One detail that helps both you and your doctor narrow down the cause is whether the black spot appears in one eye or both. You can test this easily by covering each eye in turn and checking whether the spot persists. A floater from a vitreous change will appear in whichever eye it’s in, typically just one. A scotoma from macular degeneration may be in both eyes, especially in advanced cases, though it often starts in one. Vascular events like amaurosis fugax are almost always monocular, affecting just one eye at a time. Migraine auras can produce visual disturbances in both eyes simultaneously because the origin is in the brain, not the eye itself.
If a spot shows up in both eyes at the same time and persists, the cause is more likely neurological or systemic rather than a problem with one eye’s internal structures. This distinction does not replace a professional exam, but it gives you useful information to relay to whoever evaluates you. Many patients understandably panic at a new visual symptom and forget to check which eye is affected before the episode resolves, so making a habit of covering one eye when something odd appears can save time and guide the diagnostic process.
Spots That Come and Go Versus Spots That Stay
Duration is another useful clue. Floaters are persistent but move around; they are always there if you look for them in the right light. Migraine visual phenomena build up over minutes, move across the visual field in a predictable pattern, and resolve within an hour. Amaurosis fugax blacks out part or all of one eye’s vision for seconds to minutes and then clears. A scotoma from macular degeneration or a macular hole, on the other hand, is fixed and permanent unless the underlying condition is treated.
A brief flash-like spot that appears once and never returns is almost never something to worry about. A spot that recurs in the same location, gradually grows, or is accompanied by new symptoms deserves professional evaluation. The general principle is that stability over time is reassuring, while change in any direction, whether the spot gets bigger, darker, more numerous, or is joined by flashes or vision loss, means something may be progressing and warrants a closer look.