Why Do I See Purple Spots? Causes and When to Worry

Purple spots in your vision are usually not a sign of eye damage. Most come from your eyes and brain working normally after an unusual input, like a bright light or pressure on the eyeball. The color itself rarely tells you much, because the visual system fills in hues on its own when it is pushed off balance. What matters is how the spots behave, and a sudden change in your vision is the kind that needs a doctor quickly.1Metro Eye Care. Why Do I See Purple Spots? Causes and When to Worry

Purple Spots After Looking at a Bright Light

An afterimage is a spot that stays in view after you look away from something bright, often in a color opposite or shifted from the original. A white or yellow light, for example, often leaves a purple, blue or dark green spot. At everyday light levels, nerve cells in the retina that carry signals to the brain rebound after the light stops, and that rebound becomes the spot you see.2PubMed Central. Neural Locus Of Color Afterimages Many textbooks blame tired light-sensing cells instead, but that is only true for very intense light.3PubMed Central. Neural Locus Of Color Afterimages

Very bright light behaves differently. Light strong enough to use up much of the light-sensing pigment in your eye creates a stronger, longer afterimage.4PubMed Central. Neural Locus Of Color Afterimages Once the pigment is used up, the eye catches less light in that spot until it recovers.5PubMed Central. The non-opponent nature of colour afterimages So a camera flash or a glance at the sun can leave a spot for many seconds or a few minutes. Laser pointers aimed into the eye are another matter: they can cause real damage, from small injured patches to bleeding in the retina and a lasting blind spot.6PubMed Central. Retinal Injury Following Laser Pointer Exposure A spot that lingers after a laser or sun exposure needs an eye exam.

A normal afterimage floats wherever you look and moves with your eyes rather than staying on the object that caused it. It changes color and fades over seconds to a minute or two. It looks clearest against a plain wall or with your eyes closed, and if both eyes looked at the light, both usually see it. A smudge on your glasses or a screen behaves differently, since it stays fixed relative to the glass, not to your retina.

You can test a spot yourself. Blinking, or looking at a dim neutral surface, helps an afterimage fade faster. If a spot keeps the same shape and color for hours, it isn’t an ordinary afterimage. Never look at the sun or a laser to recreate one.

Purple Spots When You Rub or Close Your Eyes

Pressing on your eyes can make you see colors.7Duke Department Of Ophthalmology. Whats Really Happening When We See ‘Stars’ After Rubbing Our Eyes? Your visual system produces its normal signals when something other than light, such as pressure, stimulates it.8Duke Department Of Ophthalmology. Whats Really Happening When We See ‘Stars’ After Rubbing Our Eyes? So purple, blue or checkered patterns while rubbing your eyes are expected and harmless. Faint colors and dots in total darkness with your eyes closed are also normal, a light the eye makes on its own.9PubMed. ‘Visual snow’ – a disorder distinct from persistent migraine aura

Pressing on the eyeball stimulates retinal cells mechanically, and the brain reads that as light. The pattern appears on the side opposite where you press, because light from that side of the world would land on the part of the retina you are squeezing. Purple, blue, white, and checkerboard or lattice shapes are all common.

Other everyday triggers produce brief spots too. Standing up fast can briefly darken vision with spots as blood pressure dips, and a hard sneeze, cough or straining can do the same. These pass within seconds once you sit or breathe normally.

Hard, frequent rubbing irritates the eye and may come from allergies or dryness that are worth treating. A cool compress or eye drops work better than rubbing. Flashes that keep appearing without any rubbing are different, and they belong with the warning signs below.

Migraine Aura and Colored Spots

An aura is a visual disturbance that often comes before or with a migraine. It typically grows slowly from a small spot into a larger shimmering or zigzag shape.10PubMed Central. Symptoms related to the visual system in migraine A wave of strong nerve activity followed by quieting moves across the back of the brain, where vision is handled.11PubMed Central. Differential Diagnosis of Visual Phenomena Associated with Migraine: Spotlight on Aura and Visual Snow Syndrome The spot spreads at about the speed of that wave, which is why it takes minutes rather than seconds.12PubMed Central. Symptoms related to the visual system in migraine Because the cause is in the brain, an aura appears in the same place whether you close one eye or the other, unlike an eye problem.

To the person having it, the shape is often a small bright or shimmering spot near the center or side of vision. It grows into a C-shaped or zigzag arc with a jagged, flickering edge, sometimes compared to heat shimmer or a fortress wall. Colors vary. Some people see mostly silver or white, others purples, blues or rainbow edges, so purple alone doesn’t make an aura more or less likely. It doesn’t go away when you close your eyes and may even look clearer then, which helps tell it from a spot on your glasses or a mark on a screen.

An aura usually builds over about 5 minutes and lasts under an hour. A headache may follow, though some people get aura without pain. As the spot moves, it can leave a blank or blurry area behind it.

Some aura-like spots are not a migraine. A first-ever aura after age 50 should be checked. Aura with weakness, slurred speech or a drooping face needs emergency care. An aura that starts suddenly at full size rather than spreading is also less typical. If auras become frequent, see a doctor about prevention options.

Floaters, Flashes and the Retina

Floaters and flashes most often come from the clear gel filling the eye shrinking and pulling away from the back of the eye with age.13Elsevier / Ageing Research Reviews. Ageing of the vitreous: From acute onset floaters and flashes to retinal detachment Floaters are the small shapes that drift through your vision, and they can look like gray, dark or purplish dots, threads or cobwebs that move as you move your eyes. As the gel tugs on the retina, it can trigger flashes of light, especially at the edge of vision. The same pulling can also tear the retina and lead to a retinal detachment.14Elsevier / Ageing Research Reviews. Ageing of the vitreous: From acute onset floaters and flashes to retinal detachment

As the gel shrinks it separates from the retina. For most people the separation finishes without a tear, and the floaters and flashes gradually settle. The risk is a spot where the gel is stuck firmly and tears the retina as it peels away. That is why a new burst of symptoms deserves a dilated exam even though most turn out harmless.

Floaters drift and lag behind when you move your eyes, then settle. They show best against a bright sky or a white screen. Unlike afterimages, floaters stay for weeks or longer.

They are common from middle age onward. Nearsighted people often notice them earlier, and past eye surgery or eye injury raises the chance.

Most floaters become less noticeable over months as the brain learns to ignore them. For floaters that keep interfering with daily life, surgery to remove the gel is an option, though it carries real risks and is usually reserved for severe cases.15PubMed. To Treat or Not to Treat: Management Options for Symptomatic Vitreous Floaters A laser treatment that breaks up floaters has also become more common.16PubMed Central. Safety and Efficacy of YAG Laser Vitreolysis for the Treatment of Vitreous Floaters: An Overview

Other eye conditions can show dark spots as well. Fluid under the retina can cause a blurry dark spot in the center of one eye, with straight lines looking wavy.17PubMed Central. Central Serous Chorioretinopathy: Pathogenesis and Management Colors may look washed out and objects smaller in that eye.18PubMed Central. Central Serous Chorioretinopathy: Pathogenesis and Management Any of these needs a prompt eye exam rather than waiting.

Medicines and Eye Surgery That Change Color Vision

Erectile dysfunction pills such as sildenafil (Viagra) can give vision a temporary blue or violet tint.19PubMed Central. Acquired Dyschromatopsia and Its Link to Drug Toxicity They affect the chemical steps color-sensing cells use to respond to light.20PubMed Central. Acquired Dyschromatopsia and Its Link to Drug Toxicity Because this is a chemical change rather than injury, a tint that appears an hour or so after a dose is a known side effect, and it wears off as the drug leaves the body, usually within hours. It is more likely with higher doses, so if it bothers you or interferes with driving at dusk, tell the prescriber.

Long-term hydroxychloroquine, used for lupus and arthritis, is a different case. It can damage the retina and leave ring-shaped blind spots.21PubMed. Disparity between visual fields and optical coherence tomography in hydroxychloroquine retinopathy People taking it need regular eye screening that includes a visual field test.22PubMed. Disparity between visual fields and optical coherence tomography in hydroxychloroquine retinopathy

If a medicine seems to tint your vision, note the timing between the dose and the color change. Don’t stop a prescribed medicine without asking the prescriber. Seek care if vision drops suddenly rather than just looking tinted.

Lens implants can cause colored images too. After cataract surgery, a shifted implant can create unusual colored shapes; one man could see the colored edge of his slipped lens.23PubMed. Chromatic visual phenomenon caused by a subluxed intraocular lens New colored shapes after cataract surgery are worth reporting to your surgeon.

Constant Dots Everywhere Could Be Visual Snow

Visual snow is a nonstop static of tiny dots over the whole field of vision, like an old TV screen. More than a third of people with it also have long-lasting afterimages, trails behind moving things, light sensitivity and poor night vision.24PubMed. ‘Visual snow’ – a disorder distinct from persistent migraine aura They also become unusually aware of normal eye effects such as floaters and self-made light.25Springer Nature. How do I recognise and manage visual snow syndrome? Brain scans show differences in the visual areas of the brain in people with visual snow.26Oxford Academic (Brain Communications). Microstructure in patients with visual snow syndrome: an ultra-high field morphological and quantitative MRI study It is separate from a migraine aura that simply never ends.27PubMed. ‘Visual snow’ – a disorder distinct from persistent migraine aura

Ordinary spots come and go with a trigger like a light, pressure or a migraine. Visual snow is present all the time, in both eyes, and across the whole visual field, including with the eyes closed in some people. The dots are tiny and flicker like static, rather than drifting like floaters or fading like afterimages, and that grainy movement is what people usually describe first. It is not dangerous to the eyes, but it can be tiring and distressing.

A normal eye exam is expected, because the problem sits in the brain. A neurologist familiar with visual snow is usually the right specialist. Mention migraines and any recreational drug use, since both shape the diagnosis.

When Purple Spots Need Urgent Care

These signs point to the retina and can mean a tear or detachment, which needs care the same day:28Eye florida. When Vision Symptoms Need Urgent Eye Care Help

  • A sudden burst or shower of new floaters
  • Flashes that keep coming, especially in a dark room
  • A dark curtain, veil or shadow moving across part of your vision
  • New floaters or flashes after a hit to the eye or head

Other warning signs involve the brain or blood supply. Sudden blur, missing patches or a gray area in one eye that was clear before is a warning sign.29Eye florida. When Vision Symptoms Need Urgent Eye Care Help Spots with trouble speaking, a drooping face, weakness or dizziness may mean a stroke, and you should call emergency services.30Eye florida. When Vision Symptoms Need Urgent Eye Care Help Eye pain with light sensitivity, nausea, or vision loss with redness also needs fast care.31Eye florida. When Vision Symptoms Need Urgent Eye Care Help Blocked blood vessels in the eye can cause sudden vision loss even in young adults.32PubMed Central. Combined central retinal vein and cilioretinal artery occlusion in a 25-year-old woman

For retina symptoms, an eye doctor’s urgent slot or an emergency room both work. Stroke signs always mean emergency services, not an eye clinic. Don’t wait to see if it clears up, since early repair saves more vision.33Metro Eye Care. Why Do I See Purple Spots? Causes and When to Worry

Tell the doctor when it started and whether it came on suddenly. Cover each eye in turn to learn whether it is in one eye or both. Mention any injury, headache, new medicine or recent surgery.

What an Eye Exam Checks

Dilating drops let the doctor look at the whole retina for tears, bleeding or swelling. They open the pupil wide enough to see the retina all the way to its far edges, where tears often occur; without them only the center can be seen well. The drops take about 15 to 30 minutes to work, so you may wait a while before the retina exam begins.

Swollen nerve heads, bleeding and pale patches in the retina can reveal a blocked vessel.34PubMed Central. Combined central retinal vein and cilioretinal artery occlusion in a 25-year-old woman A scan of the back of the eye measures the layers of the retina and can help spot areas where vision is lost.35PubMed. Optical coherence tomography measurement of nerve fiber layer thickness and the likelihood of a visual field defect Scans alone can miss some damage, so a field-of-vision test is still useful.36PubMed. Disparity between visual fields and optical coherence tomography in hydroxychloroquine retinopathy In that test you click a button when lights appear at the edges of your view.

Dilated pupils blur vision and cause glare for several hours, so bring sunglasses and arrange a ride if possible. Bring a list of your medicines.