COVID-19 can have various effects on vision, ranging from temporary irritations to more serious, albeit less common, conditions. The impact on the eyes can stem from both the direct presence of the virus and the body’s broader systemic response to the infection. While many ocular symptoms are mild and resolve on their own, some may require professional attention, particularly if they persist or involve significant changes in vision. Understanding these potential effects can help individuals recognize when to seek care.
How COVID-19 Can Affect Vision
The mechanisms by which COVID-19 influences eye health involve both direct viral action and indirect systemic responses. The virus, SARS-CoV-2, can directly infect eye tissues, such as the conjunctiva, the mucous membrane covering the white part of the eye and the inside of the eyelids. This direct infection can lead to conditions like conjunctivitis, commonly known as pink eye. Evidence suggests the virus can potentially reach the retina, located at the back of the eye, even when initial infection occurs through inhalation.
Beyond direct infection, the body’s reaction to the virus can significantly impact vision. Systemic inflammation, a widespread response to COVID-19, can affect blood vessels and nerves that supply the eyes. This inflammation can lead to micro-clots, blocking blood flow to parts of the eye or the optic nerve. Furthermore, COVID-19 can affect the nervous system, potentially disrupting functions like pupil size or impacting how nerve cells in the brain receive resources.
Reported Vision Problems
Individuals with COVID-19 have reported a range of specific vision problems and symptoms. Common ocular symptoms include conjunctivitis, characterized by redness, itching, discharge, and eye pain or discomfort. Dry eyes and light sensitivity, also known as photophobia, are frequently reported. Approximately 10% of COVID-19 patients experience at least one eye problem, with conjunctivitis being the most common, affecting about 20% of those with ocular symptoms.
Visual disturbances can also occur, such as blurred vision, floaters, and double vision. Blurred vision can sometimes be a result of headaches or dizziness associated with the infection. While less common, more severe conditions have been reported.
These include optic neuritis, an inflammation of the optic nerve that can cause vision loss, often occurring after the acute infection. Retinal vascular occlusions, blockages in retinal blood vessels due to clots, can also cause blurred vision or sudden vision loss. Rarer conditions like acute macular neuroretinopathy (AMN), affecting the macula, have also been observed in some cases following COVID-19 infection.
Persistent Vision Issues After COVID-19
Some vision problems experienced during or after COVID-19 can persist for weeks or months, forming part of what is known as “Long COVID” or post-acute sequelae of COVID-19 (PASC). Persistent blurred vision, ongoing dry eyes, and prolonged light sensitivity are among the visual issues that can linger. These issues can significantly impact daily activities, including reading or using screens.
Research is ongoing to understand why these vision problems endure, distinguishing them from the acute phase of the illness. Studies have indicated that long COVID patients can experience a decrease in blood flow in the smallest blood vessels in the retina. This reduced circulation in the eye may reflect similar issues in other parts of the body, including the brain, potentially contributing to broader neurological symptoms associated with Long COVID.
When to Consult an Eye Care Professional
It is important to seek medical attention for vision changes during or after a COVID-19 infection. If you experience sudden vision loss, severe eye pain, or persistent blurred vision, it is advisable to consult an eye care professional promptly. Other concerning symptoms that warrant evaluation include new floaters or flashes of light, double vision, or any worsening or concerning visual symptoms.
Timely evaluation can help determine the cause of the symptoms, rule out serious underlying conditions, and allow for appropriate management. An eye doctor can perform a comprehensive eye exam to assess visual acuity and examine the structures of the eye. This is particularly important for individuals with pre-existing eye conditions or those with risk factors for vascular problems.