If you have been suffering from eye problems since contracting COVID-19, you are not alone. Some people have reported ocular symptoms such as dry eyes, tearing, and blurred vision following a COVID-19 infection. While most COVID and long COVID eye problems are mild and go away on their own, some can linger and have unsettling effects, such as blind spots or sudden vision loss.
Here, we take a closer look at COVID’s effects on the eyes and explain the causes and potential treatments for these conditions.
Can COVID-19 cause eye problems?
Approximately 1 out of 10 COVID-19 patients exhibit at least one ‘ocular manifestation’ or eye problem while infected. This is according to a 2021 systematic review and meta-analysis published in the Journal of Ophthalmic & Vision Research.
The review noted that conjunctivitis was the most common eye-related symptom in COVID-19 patients. Conjunctivitis is also reported in studies as an early sign of COVID-19 diagnosis. In fact, many eye symptoms tend to manifest a few hours or days before respiratory and systemic symptoms show up.
Eye symptoms caused by COVID-19
COVID-19 patients have reported the following eye issues:
- Dry eyes
- Foreign body sensation
- Blurry vision
- Conjunctivitis or pink eye
- Photophobia or light sensitivity
- Eye pain
Some patients also experience vision-related symptoms that don’t necessarily cause obvious changes to the eyes or vision, such as:
- Motion sickness
- Difficulty focusing when reading
- Feeling easily overwhelmed in large crowds
Symptoms of COVID-19
As mentioned, eye symptoms usually occur shortly before infected patients show more common signs of COVID infection, such as:
- Nasal congestion or runny nose
- Sore throat
- Loss of taste or smell
- Shortness of breath or difficulty breathing
- Fever or chills
- A general feeling of being unwell or malaise
- Body aches
Causes of eye symptoms after COVID-19
Some experts believe that eye symptoms occur in some COVID patients because of the way the virus infects cells.
SARS-CoV-2 infects the body by binding to ACE2, a protein found in various types of cells and tissues in the lungs, blood vessels, gastrointestinal tract, kidneys, liver, and inner and middle ear. Think of ACE2 as a doorway that lets the virus into the body. Once inside, the virus then hijacks healthy cells and makes copies of itself, spreading throughout the body like wildfire.
There are ACE2 receptors in the eye cells, albeit in smaller amounts than in the lungs and blood vessels. Thus, it is possible for COVID to enter the body through the eyes and begin infection there. However, the likelihood of the eyes being the main ‘gateway’ of infection is low.
Another potential cause of eye symptoms after COVID is inflammation. In certain people, a COVID-19 infection kicks their immune system into overdrive, causing severe inflammation all over the body. This level of inflammation can eventually lead to respiratory distress and damage to healthy cells, tissues, and organs. As such, a large chunk of patients who develop eye conditions with COVID are those who experienced severe symptoms while infected.
However, not all eye symptoms are directly related to the novel coronavirus. Some researchers believe that some cases of eye irritation, dry eye, and foreign body sensation may not be due to COVID infection but rather other pandemic-related factors.
One theory is that wearing loose face masks causes people to expel air towards their eyes, creating dry eye symptoms. Another theory is that increased screen time during the early days of the pandemic may have aggravated irritation and dry eye sensation.
Common eye complications that develop after COVID infection
COVID-related eye problems are usually mild and resolve on their own. However, there have been recorded cases of eye problems leaving lasting effects.
A recent study revealed that many of these issues impact the retina, a layer of tissue that coats the back of the eye. The retina helps people process visual information by converting light into electrical signals. As such, eye issues that affect the retina can often be vision- threatening.
Post-COVID, also known as long COVID, eye problems tend to develop within one to six weeks after COVID infection. Certain people are also more at risk of developing complications than others, including people with conditions like:
- Blood disorders
- Conditions affecting the blood vessels
The most common long COVID eye problems involving the retina include:
Cotton wool spots
Cotton wool spots are tiny white, ‘fluffy’ spots (resembling cotton wool) that appear on the retina. These spots show up when the retinal blood vessels do not receive enough blood due to clotting. Essentially, what happens is that the tissues in the retina die from not receiving enough nutrients.
Cotton wool spots don’t typically affect vision and usually resolve over time. However, that doesn’t mean they should just be ignored. Cotton wool spots may be indicative of a more serious condition such as diabetes, HIV, cat-scratch disease, and a spate of other systemic and infectious diseases.
Also called retinal artery occlusion, eye stroke is the result of blood clotting in the retinal arteries. Without enough oxygen in the arteries, the retinal cells die, leading to sudden and painless vision loss.
Retinal vein occlusion
Retinal vein occlusion happens when tiny veins (the blood vessels that transport blood away from organs and towards the heart) in the retina become blocked. This is usually a result of a hardened artery pressing against a vein, causing blood to clot. The pressure from the blockage leads to swelling, bleeding, and fluid leaks.
Retinal vein occlusion can cause blurry or missing vision in a part of the eye, dark spots in your vision, pressure behind the eye, and, in extreme cases, permanent blindness.
Retinal hemorrhage happens when the blood vessels in the retina start bleeding. It can happen without symptoms and may cause sudden or gradual vision loss.
Can COVID-19 cause Temporary/Permanent blindness or visual impairment?
There is no definitive evidence that the COVID-19 virus itself causes blindness or visual impairment. However, complications stemming from COVID infection can potentially damage tissues in the eyes and impact eye health.
Severe cases of COVID-19 typically lead to respiratory distress, which deprives tissues of oxygen. It is possible that when eye cells and tissues are deprived of oxygen, this can lead to the aforementioned eye complications. COVID-19 can also cause multisystem inflammatory syndrome, which can lead to increased pressure inside the skull and, eventually, vision loss.
It should be noted that these complications only happen in rare cases. One study from 2021 showed that long-term eye complications from COVID infection are unlikely or rare after recovery.
Treatment for Post-COVID eye problems
Mild ocular manifestations like conjunctivitis are typically self-limiting. In other words, they usually resolve on their own. Thus, the best treatment for these kinds of symptoms is often just over-the-counter medication that provides relief, such as eye drops, creams, etc.
For retinal manifestations, on the other hand, treatment varies depending on the exact issue. For cotton wool spots, which don’t have a specific cure, an eye doctor might recommend seeking out and addressing any underlying conditions as part of the treatment plan.
Retinal vein occlusions and eye stroke cannot be cured. But doctors can help patients manage symptoms and avoid complications with:
- Anticoagulants, or medication that prevents blood clots from happening
- Laser therapy
- Anti-vascular endothelial growth factor drugs
- Eye massages
Of course, prevention is always better than cure. Some of the things you can do to protect your eyes include:
- Avoiding touching or rubbing your eyes
- Washing your hands before touching any part of your face
- Maintaining a safe distance from others, especially if they are coughing or sneezing
- Wearing a mask in crowded spaces
- Wearing protective eyewear
- Not wearing contact lenses when you are sick
- Disinfecting high-touch surfaces
When to see a doctor
You should always consult a doctor if you observe symptoms of COVID-19. Any sudden vision changes, eye pain, trauma to the eyes, discharge, and light sensitivity also merit a visit to the doctor.
The bottom line
It can be stressful to consider that eye problems may persist long after you have gone through a COVID-19 infection. But bear in mind that, while not impossible, sudden loss of vision is a rare complication of long COVID.
Only 1 in 10 patients infected with COVID experience some kind of eye symptom. And these often turn out to be manageable with over-the-counter medication.
Still, we should not take eye health for granted. If you do not want to risk getting an eye condition from COVID, be more proactive about protecting yourself from the virus. In other words, get vaccinated, mask up, wash your hands regularly, and maintain a safe distance from others.