COVID-19, caused by the SARS-CoV-2 virus, has affected millions globally. While primarily known for respiratory effects, it can manifest with a wide array of symptoms impacting various organ systems. Understanding these symptoms helps individuals seek appropriate medical guidance.
Blurred Vision and COVID-19
Blurred vision has been reported with COVID-19, though it is not a common initial symptom. Approximately 1 in 10 patients may experience at least one eye problem, including blurred vision. This symptom can appear at various stages, sometimes as an early sign, and typically resolves within a few days to two weeks. For some, however, blurred vision can persist as part of long COVID, indicating prolonged effects.
While blurred vision can occur, it is generally not a direct result of the virus directly impacting visual acuity. Instead, it often arises from associated conditions or systemic effects, such as severe dry eyes or neurological complications. Blurred vision directly attributable to COVID-19 is less common than other ocular symptoms. It is more frequently observed in individuals with severe disease or as part of post-COVID symptoms.
Other Ocular Manifestations
Beyond blurred vision, COVID-19 can lead to several other eye-related symptoms, collectively referred to as “COVID eyes.” Conjunctivitis, or pink eye, is the most frequently reported ocular manifestation, affecting an estimated 1% to 20% of patients. This inflammation of the eye’s outer surface can present with redness, itching, a gritty sensation, and watery discharge. In some instances, conjunctivitis may be the first or only symptom.
Many individuals also experience dry eyes, which can lead to discomfort and vision changes. Light sensitivity, or photophobia, is another reported symptom, where bright lights cause discomfort or pain. Eye pain, swelling, and excessive tearing have also been noted. These diverse ocular signs highlight the varied ways the infection can influence eye health.
Mechanisms of Vision Impact
Mechanisms of vision changes from COVID-19 involve various physiological responses. One pathway involves systemic inflammation, where the body’s immune response triggers widespread inflammation affecting ocular tissues. This inflammatory cascade, sometimes called a “cytokine storm” in severe cases, can damage delicate eye structures, including the retina and its blood-retinal barrier. The SARS-CoV-2 virus can breach this barrier, leading to a hyperinflammatory response and cell death in the retina, potentially causing long-term visual impairment.
Another factor is direct viral invasion of eye cells. The SARS-CoV-2 virus can bind to ACE2 receptors present on cells within the eye, including the ocular surface and retina. This direct infection can lead to localized inflammation and damage. Additionally, the virus can impact the eye through neurological pathways, affecting the optic nerve or brain areas that control vision. This can manifest as optic neuritis, cranial nerve palsies affecting eye movement, or disruptions in the autonomic nervous system that control pupil size and focus.
Changes in the body’s vascular system also contribute to vision problems. COVID-19 can increase the risk of blood clot formation, which may travel to the eye and cause blockages in retinal arteries or veins, leading to conditions like retinal artery occlusion or retinal vein occlusion. These blockages can result in reduced blood flow and oxygen supply to the retina, causing tissue damage and potentially sudden vision loss. Some medications used to treat COVID-19, such as decongestants, can also contribute to eye dryness, indirectly affecting vision.
Seeking Medical Advice
Seek medical attention if you experience new or worsening eye symptoms during or after a COVID-19 infection. While many ocular symptoms related to COVID-19 are mild and temporary, some can indicate more serious underlying issues. Consult an ophthalmologist or general practitioner if blurred vision persists, significantly worsens, or is accompanied by other concerning signs.
Immediate medical care is warranted for specific “red flag” symptoms. These include sudden vision loss, severe eye pain, double vision, or significant changes in your visual field. Prompt evaluation by an eye care professional can help determine the cause and ensure timely intervention if a vision-threatening condition is present.