Experiencing brief flashes or afterimages of color is a common phenomenon that can have various causes. While it may seem alarming, in most cases it is harmless and requires no treatment. This article explores potential reasons for seeing random colors and when to seek medical advice.
What Are Phosphenes?
The technical term for seeing colors and light without light actually entering your eye is “phosphenes.” Phosphenes can manifest in several ways:
– Brief sparkles, flashes, or streaks of light in your field of vision
– Momentary blobs or clouds of color that seem to float by
– Geometric patterns or pulsating colors behind your closed eyelids
Phosphenes occur within the visual system and are not caused by external light sources. Rather, they are the result of activity within the brain and retina.
Common Causes of Phosphenes
There are many potential causes of phosphenes, most of which are harmless:
– Rubbing your eyes – Rubbing places pressure on the retina, resulting in phosphenes. These tend to take the form of amorphous blobs or clouds of color.
– Sneezing with closed eyes – Rapid eye movements under closed lids during a sneeze can trigger phosphenes. They may manifest as streaks or geometric patterns.
– Coughing – Like sneezing, coughing can prompt eye movements that lead to phosphenes.
– Standing up quickly – A sudden change in blood pressure upon standing can temporarily alter retinal blood flow, generating flashes of light or color.
– Migraine aura – Up to 20% of migraine sufferers experience an “aura” phase before headaches occur. Auras involve visual disturbances like phosphenes, often in a zigzag pattern.
– Medications – Certain prescription drugs, like digoxin and sildenafil, can rarely cause phosphenes as a side effect.
– Electrical stimulation – Transcranial magnetic stimulation and electroconvulsive therapy introduce electrical currents that stimulate the visual cortex, eliciting phosphenes.
When to Seek Medical Advice
In most instances, phosphenes are benign and require no intervention. However, occasionally they can signal an underlying medical condition that warrants evaluation. Contact your doctor promptly if you experience:
– Prolonged or frequent phosphenes affecting both eyes
– Phosphenes accompanied by other visual disturbances like blurred vision or flashes of light
– Headaches and phosphenes together, which may indicate migraine
– Phosphenes following head trauma, which could signify concussion or brain injury
– Disorientation or confusion along with phosphenes
Rarely, persistent phosphenes may result from issues like retinal detachment, optic neuritis, or brain lesions. Though unlikely, it’s important to exclude these through an exam.
When Phosphenes Are Normal
On the other hand, the following characteristics suggest benign phosphenes:
– Lasting just a few seconds or minutes
– Sparkles, colors, or geometric patterns
– Occurring when rubbing eyes or upon coughing/sneezing
– Following exercise, sex, or sudden standing
– Absent of other neurological symptoms
– Resolving on their own without treatment
If your symptoms match this profile, rest assured your phosphenes are nothing to worry about. You can simply relax until they disappear.
Phosphene Triggers to Avoid
While innocuous, excessive phosphenes can still be annoying or distracting. You can reduce their frequency by avoiding known triggers:
– Rubbing eyes vigorously
– Straining or applying pressure during bowel movements
– Blinking excessively when tired
– Skipping regular eye exams and vision corrections
– Taking unnecessary medications linked to phosphenes
– Looking at bright screens in the dark
Making simple lifestyle adjustments like these can go a long way in preventing excessive phosphenes.
When Phosphenes Indicate Disease
In rare cases, persistent phosphenes may arise from underlying medical conditions:
| Condition | Cause of Phosphenes |
|---|---|
| Migraine with aura | Neurological disturbances in visual cortex |
| Stroke | Reduced blood flow to visual areas of brain |
| Brain tumor | Pressure on or damage to visual cortex |
| Multiple sclerosis | Demyelination of optic nerve fibers |
| Parkinson’s disease | Neurodegeneration affecting visual processing |
While rare, these warrant medical evaluation, especially when accompanying neurological symptoms are present.
When to See an Ophthalmologist
An eye doctor should evaluate persistent phosphenes to identify potential ocular causes like:
– Retinal detachment – Separated retina stimulates phosphene perceptions
– Vitreous detachment – Same effect due to detached vitreous gel
– Eye trauma – Inflammation or damage to retina, lens, or optic nerve
– Glaucoma – Increased pressure damages optic nerve
– Cataracts – Clouding of lens alters light transmission to retina
– Macular degeneration – Retinal cell death in central vision
Again, most phosphenes resolve on their own. But a thorough eye exam can provide peace of mind by ruling out problematic conditions.
Diagnosing the Cause of Phosphenes
To discern the exact cause of troublesome phosphenes, the following diagnostic steps may be undertaken:
– Medical history – Identify any underlying conditions, medications, or recent head trauma
– Visual exam – Assess eyes and optic nerve for abnormalities
– Brain imaging – CT or MRI scan to exclude lesions, swelling, or stroke
– Electroretinography – Measures retinal electrical responses
– Visual field testing – Maps out areas of vision loss
– Blood tests – Check for infections, autoimmune issues, or nutritional deficiencies
The results can then guide appropriate treatment when warranted.
Treatments for Pathological Phosphenes
Treatment will depend on the specific cause identified:
– Migraines may be treated with preventative medications like beta blockers or anti-seizure drugs
– Stroke requires emergency care to restore blood flow
– Tumors may necessitate surgery, radiation therapy, or chemotherapy
– Inflammation can be addressed with steroids and immunomodulators
– Underlying conditions like diabetes or high blood pressure are managed per standard protocols
– Retinal issues may need cryotherapy, laser treatment, or surgical repair
Symptomatic relief is also possible in some cases through medications like gabapentin, amitriptyline, or clonazepam. But identifying and addressing the root cause is the priority.
Lifestyle Changes to Minimize Phosphenes
For benign phosphenes unrelated to disease, simple lifestyle measures can help reduce occurrences:
– Take frequent breaks when doing intensive near work or computer use
– Wear sunglasses when outdoors to avoid overstimulating retina
– Use artificial tears to lubricate eyes if dryness is an issue
– Improve posture to increase blood flow to head and eyes
– Avoid rubbing eyes forcefully
– Treat headaches, coughs, colds, and allergies promptly
– Reduce stress through relaxation techniques
– Ensure proper sleep, nutrition, and hydration
– Have annual eye exams to detect any problems early
With some minor adjustments, benign phosphenes can often be minimized without the need for intervention.
When to Seek Emergency Care
Rarely, phosphenes may signal a true ophthalmologic or neurologic emergency requiring urgent evaluation, like:
– Sudden loss of vision or pupils of unequal sizes – may indicate stroke, bleeding, or retinal detachment
– Phosphenes after head injury – could signify concussion, cranial bleed, or traumatic brain injury
– Accompanying numbness, weakness, vertigo, or confusion – suggests CNS disorder
– Optic nerve inflammation signs like eye pain or swelling
– Uncontrolled flashes of light and floaters – could mean retinal tear or detachment
In these situations, call 911 or seek emergency care without delay to prevent permanent vision or brain damage.
Conclusion
While disconcerting, fleeting phosphene perceptions are seldom cause for concern. But those arising from true medical conditions can potentially threaten vision or neurological function if left untreated. Seeking timely diagnostic evaluation is key, especially when worrisome symptoms accompany the phosphenes. With appropriate care guided by an understanding of the cause, even pathological phosphenes can often be effectively managed.
