Many individuals experience visual disturbances described as “seeing spots,” which commonly refer to eye floaters and flashes. These phenomena, while often unsettling, are generally harmless visual experiences. They stem from changes within the eye’s internal structures, creating perceptions of moving specks or brief light sensations.
Understanding Floaters and Flashes
Floaters are perceived as tiny specks, dots, lines, or cobweb-like structures that drift across the field of vision. They are small bits of protein or cellular debris within the vitreous humor, the clear, jelly-like substance filling the eyeball. These particles cast shadows onto the retina, which the brain interprets as floaters. Floaters become more noticeable against plain, bright backgrounds like a clear sky or a white wall.
Flashes, also known as photopsias, appear as brief streaks or flashes of light, similar to seeing lightning or camera flashes. They occur when the vitreous humor pulls on or rubs against the retina. This mechanical stimulation generates an electrical signal the brain perceives as a flash of light. Floaters and flashes can occur together or independently.
Common Reasons You See Spots
The most frequent cause of floaters is the natural aging process. As individuals age, typically over 50, the vitreous humor liquefies and shrinks. This process can lead to the clumping of collagen fibers within the vitreous, forming the shadows seen as floaters.
Posterior Vitreous Detachment (PVD) is a common age-related change where the vitreous gel separates from the retina. This separation often causes a sudden increase in floaters, sometimes described as a “cobweb” or a Weiss ring, and can also produce occasional flashes. PVD is a normal part of aging and is generally not painful or vision-threatening.
Less common, benign causes for floaters include mild eye inflammation, where inflammatory cells can cause visual disturbances. Minor, temporary changes in retinal blood vessels can also release small blood cells into the vitreous, which are then perceived as floaters.
When Spots Signal a Serious Issue
While many floaters and flashes are harmless, certain symptoms warrant immediate medical attention. A sudden increase in floaters, particularly a “shower” of many new ones, or new flashes of light, especially when accompanied by changes in vision, are concerning signs. These symptoms could signal a retinal tear or detachment, which are medical emergencies.
A retinal tear occurs when the vitreous gel, as it pulls away, tugs with enough force to create a rip in the retina. Symptoms include a sudden onset of new floaters and flashes, and potentially blurred vision. If fluid leaks through this tear, it can cause the retina to pull away, leading to a retinal detachment.
A detached retina is characterized by a dark curtain or shadow developing in peripheral vision, or a sudden loss of vision. Untreated, it can lead to permanent vision loss.
Vitreous hemorrhage, which is bleeding into the vitreous gel, can also cause many new floaters or a general haziness in vision. This condition can result from various causes, including diabetic retinopathy, where abnormal blood vessels in the retina leak, or from a retinal tear.
Eye inflammation or infection, known as uveitis, can also cause floaters where inflammatory cells inside the eye can become visible. Uveitis may also present with pain, redness, light sensitivity, or blurred vision.
Visual disturbances like “scintillating scotoma,” which appear as zigzag lines or shimmering lights, are typically part of a migraine aura. These are distinct from floaters and flashes related to vitreous changes and usually resolve quickly, even without a headache. It is important to differentiate these transient phenomena from symptoms of retinal issues.
Taking Action and Seeking Care
Seek immediate evaluation from an eye care professional if you experience a sudden onset of many new floaters, new or increased flashes of light, a dark curtain or shadow obscuring part of your vision, or any sudden loss of vision. These symptoms could indicate a serious condition like a retinal tear or detachment, which requires prompt attention to preserve vision.
For isolated, long-standing floaters that have not changed, immediate emergency action may not be necessary, but a routine comprehensive eye exam is still advisable to monitor eye health. During an eye exam, an eye care professional will typically dilate your pupils to thoroughly examine the retina and the vitreous. This allows for a detailed view to identify any underlying issues.
Most benign floaters, especially those associated with PVD, do not require specific treatment and often become less noticeable over time as the brain adapts or the floaters settle. However, serious conditions like retinal tears or detachments necessitate prompt intervention. Retinal tears can often be treated with laser photocoagulation or cryotherapy to seal the tear and prevent detachment. If a retinal detachment has occurred, surgical procedures such as vitrectomy or scleral buckling are often performed to reattach the retina and prevent permanent vision loss.