How the COVID-19 delta and omicron variants could affect your eyes
As of early January, nearly all new COVID-19 cases in the U.K. and U.S. were caused by the omicron variant.
The World Health Organization labeled omicron a "variant of concern" on November 26, 2021. Since then, omicron has been detected in more than 110 countries.
Like other coronavirus variants, omicron and delta may be able to cause certain eye-related symptoms, but we don't know for sure yet.
Vaccines are less effective against the omicron and delta variants, but they're still your best form of protection.
An eye test may soon be able to help detect cases of long-haul COVID.
The COVID-19 omicron variant was discovered in November 2021, and it didn't take long to spread across most of the world. Whenever it's detected in a new location, it usually takes over delta variant infections and becomes the dominant COVID strain in a matter of weeks.
Does the omicron variant affect your eyes?
At this point, it's still too early to know how the newly discovered omicron variant might affect your eyes or vision. And that isn't the only thing we don't know about omicron.
We're still waiting for detailed information about:
How easily omicron spreads.
Exactly how well COVID-19 vaccines protect against omicron.
How severe of an illness it causes compared to other variants.
Early data suggests that the omicron variant could cause a more mild form of COVID-19 than delta and other variants. But that doesn't mean you should let your guard down.
"All variants of COVID-19 … can cause severe disease or death, in particular for the most vulnerable people," the World Health Organization notes.
They emphasize that "prevention is always key," no matter how omicron plays out.
Can the Delta variant cause eye symptoms?
We don't know for sure — yet. Previous strains of COVID could cause eye-related symptoms, but there isn't enough scientific data available right now to say with certainty that Delta does the same.
There have been isolated reports of Delta infections causing eye symptoms, including one fully vaccinated Kentuckian who had bloodshot eyes and flu-like symptoms.
Although not nearly as common as symptoms like cough and fever, other strains of the coronavirus were capable of causing:
It isn't a stretch to think that some Delta infections are capable of causing similar eye symptoms, but, like other aspects of Delta, we need to wait for more information.
While each infection is different, Delta seems to be causing slightly different symptoms overall than earlier forms of COVID.
"It seems like cough and loss of smell are less common," said Dr. Inci Yildirim, a pediatric infectious disease specialist at Yale Medicine, in an article about the Delta variant. "And headache, sore throat, runny nose and fever are present based on the most recent surveys in the U.K., where more than 90% of the cases are due to the Delta strain."
If a set of symptoms that includes runny nose, sore throat and headache sounds familiar, it's because many Delta infection symptoms resemble a bad case of seasonal allergies.
This is where eye-related symptoms could get even more confusing.
If you have bad seasonal allergies, you probably know how much allergies can affect your eyes. Red, bloodshot eyes are a hallmark symptom; itchiness, watering and even blurry vision are also common.
And while "classic" COVID symptoms are becoming less common, they can still show up. Cough, loss of taste or smell, and certain gastrointestinal symptoms still occur, but they're becoming less likely.
The three most widely available COVID-19 vaccines — Pfizer, Moderna and Johnson & Johnson — will still protect you against the delta variant, but not as effectively as they did against previous strains. Fortunately, studies continue to show that these "breakthrough" cases are less common and less severe, on average.
MIS-C: A rare but growing concern in children
As Delta finds ways to infect more young people than earlier strains, a rare but serious complication of COVID is also expected to be on the rise.
MIS-C — multisystem inflammatory syndrome in children — can cause vital organs and other parts of the body to become inflamed. It shares similarities with Kawasaki disease, a condition uncovered earlier in the pandemic.
We don't currently know why MIS-C happens to some children.
Symptoms of MIS-C can vary. It can also cause red, bloodshot eyes, but like COVID-19, it's unlikely that would be the only symptom. Additional symptoms occur alongside a fever, according to the CDC.
In addition to a fever, MIS-C symptoms can include:
Chest pain or tightness
Low blood pressure
According to the Ministry of Health and Family Welfare (MoHFW), as more children test positive for COVID, they also seem to develop MIS-C, a post-COVID complication. As per the MoHFW, MIS-C is rare but a very serious condition. It affects the age group of those between five and 18.
As of July 25, 2021, doctors reported over 400 cases of MIS-C in Bangaluru, suggesting parents get their children tested for COVID-19 without any delay. “Symptoms of MIS-C show up two to four weeks after Covid-19 infection. In some cases, the symptoms may occur after six weeks. MIS-C is the result of an immune storm: antibodies are produced in large numbers, so much so that they start affecting the heart, liver and kidneys,” said Dr Sanjay KS, the director of the Indira Gandhi Institute of Child Health to Times of India.
While rare, it is recommended that you seek emergency care if you notice symptoms such as difficulty breathing, chest pain or pressure, pale skin or any other severe symptoms.
The eyes could offer insight into long COVID cases
There's a lot we still don't know about long COVID, the symptoms that linger for weeks or months after the initial infection clears up. Sometimes, symptoms seem to continue indefinitely, significantly impacting a person’s quality of life.
Also known as "long-haul COVID" or "post-acute COVID," long COVID can show up as one or more of a multitude of symptoms. In addition to many others, ongoing symptoms can include:
Changes in taste or smell
Worsening symptoms after physical activity
We don't yet know how often long COVID occurs after a Delta infection, or among vaccinated people. Hindustan Times reports that nearly 15-20 per cent of hospitalised COVID-19 patients are returning and complaining about some of the other complications they are facing. However, these numbers may be higher, as some people experiencing long COVID symptoms like body ache, among others, might not be returning, states Dr. Vivek Nangia, head of the department of respiratory medicine at Max Hospital, Saket.
One February study found that roughly 30% of people were still experiencing symptoms between three and nine months after having COVID. About one in 12 participants reported that symptoms affected their ability to complete at least one "activity of daily living," with household chores being the most common.
Long COVID is a developing issue that will continue to affect millions of people for the foreseeable future. Standardised treatment options may not be available yet, but clues to diagnosis could lie in — of all places — the eyes.
Ophthalmologists used a painless, noninvasive test called a corneal confocal microscopy, a procedure used to diagnose several other conditions that affect the cornea.
While the study acknowledged that more research is needed, the discovery could eventually be a stepping stone toward recovery for people affected by ongoing symptoms, especially neurological.
Getting help from a medical professional
COVID-19's symptoms can be unpredictable, and, like other illnesses, it's important not to self-diagnose. People who experience symptoms are advised to follow the latest guidance from the World Health Organization (WHO), National Centre for Disease Control, MoFHW and CDC.
If you think that you or someone you know has COVID-19 or long-haul COVID, speak with a medical professional.
If you notice emergency symptoms such as difficulty breathing, chest pain or pressure, confusion or skin discolouration, seek medical attention as soon as possible.
Weekly epidemiological update on COVID-19 - 10 August 2021. World Health Organization. August 2021.
Expert reaction to cases of variant B.1.617 (the ‘Indian variant’) being investigated in the UK. Science Media Centre. April 2021.
Tracking SARS-CoV-2 variants. World Health Organization. August 2021.
Tracking of variants. GISAID. Accessed August 2021.
Delta, Alpha variants behind breakthrough Covid cases in India; no new strain. Hindustan Times. August 2021.
Coronavirus: Delta or Delta Plus variant? Which is a bigger threat and why? Times of India. August 2021.
Maharashtra's Delta Plus variant count crosses 100 after 27 new cases. NDTV. August 2021.
COVID-19 vaccine. Indian Council of Medical Research (ICMR). Accessed August 2021.
Covaxin effective against Delta Plus variant of Covid-19: ICMR study. The Indian Express. August 2021.
Doctors report 400 MIS-C cases in Bengaluru, suggest early testing of children. The Times of India. July 2021.
Hospitals see a rise in cases of post-Covid complications. Hindustan Times. June 2021.
Covid19 guidelines. National Centre for Disease Control. August 2021.
Latest updates. Ministry of Health and Family Welfare, Government of India. August 2021.
CDC COVID data tracker. Centers for Disease Control and Prevention. August 2021.
Coronavirus pandemic (COVID-19): Which vaccines have been administered in each country? Our World in Data. August 2021.
About variants of the virus that causes COVID-19. Centers for Disease Control and Prevention. August 2021.
Sore eyes as the most significant ocular symptom experienced by people with COVID-19. BMJ Open Ophthalmology. November 2020.
5 things to know about the delta variant. Yale Medicine. August 2021.
Symptoms of the delta variant vs. previous COVID-19 strains. Baton Rouge General. July 2021.
Is It COVID-19 or allergies? American Academy of Ophthalmology. January 2021.
When you’ve been fully vaccinated. Centers for Disease Control and Prevention. Accessed 6 August 2021.
Health department-reported cases of multisystem inflammatory syndrome in children (MIS-C) in the United States. Centers for Disease Control and Prevention. Accessed 16 August 2021.
For parents: Multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. Centers for Disease Control and Prevention. Accessed 16 August 2021.
MIS-C and COVID-19: Rare inflammatory syndrome in kids and teens. Johns Hopkins Medicine. July 2021.
Post-COVID conditions. Centers for Disease Control and Prevention. Accessed 6 August 2021.
Sequelae in adults at 6 months after COVID-19 infection. JAMA Network Open. February 2021.
A pandemic that endures for COVID long-haulers. The Harvard Gazette. April 2021.
Corneal confocal microscopy identifies corneal nerve fibre loss and increased dendritic cells in patients with long COVID. British Journal of Ophthalmology. July 2021.
Clinical applications of corneal confocal microscopy. Clinical Ophthalmology. June 2008.
Coronavirus. Prevention. World Health Organization. Accessed August 2021.
Symptoms of COVID-19. Centers for Disease Control and Prevention. Accessed 6 August 2021.
COVID vaccines protect against delta, but their effectiveness wanes. Nature. August 2021.
Effectiveness of COVID-19 vaccines in ambulatory and inpatient care settings. New England Journal of Medicine. September 2021.
Page published in August 2021
Page updated in January 2022