Seeing purple spots or other visual disturbances can be a curious and sometimes unsettling experience. This phenomenon, involving flashes, floaters, or colored spots, is often transient and benign. However, it can occasionally signal an underlying health issue. Understanding the various causes helps discern when such an observation is harmless and when it might indicate a more serious condition.
Temporary Visual Disturbances
Afterimages occur when the eye’s photoreceptor cells, particularly cones, become fatigued after prolonged exposure to a bright light source. Staring at a bright yellow light, for instance, can desensitize yellow-sensitive cones, leading to a temporary perception of its complementary color, such as purple or blue, when looking away.
Ocular migraines, also known as retinal migraines, commonly involve temporary visual anomalies. These can include brightly colored spots, zigzag lines, or temporary blind spots. These disturbances, called auras, can occur with or without a headache and typically resolve within minutes to an hour. They are believed to result from abnormal electrical activity in the brain’s visual cortex or temporary changes in retinal blood flow.
Physical pressure on the eye can also induce temporary visual sensations. Rubbing the eyes vigorously or standing up too quickly can mechanically stimulate the retina, leading to flashes or colored spots, sometimes described as purple. Eye strain from prolonged focus, such as extensive screen time, might also contribute to transient visual distortions. These temporary disturbances are not indicative of serious eye or health problems.
Underlying Health Concerns
Retinal issues, such as posterior vitreous detachment (PVD), can cause flashes of light (photopsias) and floaters, which some individuals might perceive as colored spots. PVD occurs when the vitreous gel, a jelly-like substance filling the eye, liquefies and separates from the retina as a natural part of aging. If the vitreous pulls too strongly on the retina during this process, it can cause flashes of light.
A more serious concern related to flashes and floaters is retinal detachment, where the retina pulls away from its supportive tissue. This condition is often painless but can lead to a shower of new floaters, flashes of light, and a dark shadow or “curtain” in the visual field. While flashes are typically described as white or clear, their perception can vary, and a sudden increase in any visual disturbance warrants immediate evaluation.
Certain neurological conditions can also manifest with visual symptoms. Transient Ischemic Attacks (TIAs), often called “mini-strokes,” involve a temporary disruption of blood flow to the brain, which can cause sudden, short-lived visual disturbances like blurry spots, temporary vision loss, or flickering. Any sudden onset of visual anomalies accompanied by other neurological signs like weakness or speech changes requires urgent medical attention. Optic nerve disorders, where the optic nerve is damaged or inflamed, can also lead to changes in vision, including blurred vision, blind spots, and altered color perception.
Some medications can also induce visual side effects, including flashes of light, floaters, or changes in color perception. For example, certain drugs can affect blood vessels or the brain’s processing of visual signals, leading to transient visual phenomena. It is important to discuss any new or worsening visual symptoms with a healthcare provider, especially if one is taking new medications.
When to Consult a Professional
Any sudden onset of new or significantly increased flashes, floaters, or colored spots should prompt an immediate evaluation by an eye care professional. This is particularly true if these symptoms are accompanied by a dark curtain or shadow moving across the visual field, which can indicate a retinal detachment. Prompt treatment for retinal detachment is essential to prevent permanent vision loss.
Other concerning symptoms that necessitate urgent medical consultation include eye pain, headache, or if the visual disturbances are persistent or worsening. If visual changes occur alongside neurological symptoms such as sudden weakness, numbness, speech difficulties, or dizziness, it could signal a stroke or TIA, requiring emergency medical care. Seeking professional medical evaluation ensures a proper diagnosis and timely intervention when needed.