Since the start of the COVID-19 pandemic in December 2019, more than 3 million people have contracted the disease worldwide. COVID-19 is caused by a newly discovered virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Viruses in the coronavirus family cause various kinds of respiratory infections, including the common cold, Middle East Respiratory Syndrome (MERS), and Severe Acute Respiratory Syndrome (SARS).

The virus that causes COVID-19 is highly contagious and can result in either mild or severe illness. According to the World Health Organization (WHO), the symptoms include:

Although less common, COVID-19 may also lead to the development of pink eye in about 1 to 3 percent of people.

In this article, we’re going to take a look at a look at why COVID-19 may cause pink eye and what other eye symptoms people with COVID-19 may experience.

It’s thought that up to 3 percent of people with COVID-19 develop ophthalmological symptoms (symptoms affecting the eyes).

In comparison, the Centers for Disease Control and Prevention (CDC) estimates that 83 to 99 percent of people develop a fever and 59 to 82 percent of people experience a cough.

A one-person study published in the British Journal of Ophthalmology found that eye symptoms occurred in the middle stages. Additional research involving more participants is needed to verify that this is typical, however.

Pink eye

Pink eye, also known as conjunctivitis, is an inflammation of the clear tissue over the whites of your eyes and the inside of your eyelids. It usually leads to redness and swelling of your eyes and can be caused by a viral or bacterial infection.

A review of studies published on April 24, 2020, examined the prevalence of pink eye among people with COVID-19.

The researchers examined 1,167 people with either mild or severe COVID-19.

They found that 1.1 percent of people developed pink eye, and that it was more common in people with severe symptoms.

Only 0.7 percent of people with mild symptoms developed pink eye, while it occurred in 3 percent of people with severe symptoms.

A study published in late February 2020 examined the COVID-19 symptoms of 1,099 people with the illness in 552 hospitals in China. Researchers found that 0.8 percent of the people with COVID-19 had symptoms of pink eye.

Chemosis

One study published in JAMA Ophthalmology examined the symptoms of 38 people who had to be hospitalized because of COVID-19. Twelve of the participants had symptoms of pink eye.

Seven of these experienced chemosis, which is a swelling of the clear membrane that covers your eye whites and inner eyelid. Chemosis can be a symptom of pink eye or a general sign of eye irritation.

Epiphora

In the same study, researchers found that seven people had epiphora (excessive tearing). One of the participants experienced epiphora as their first symptom of COVID-19.

Increased eye secretion

Seven of the participants in the JAMA Ophthalmology study experienced increased eye secretions. (Your eyes normally produce an oily film to help keep them lubricated.)

None of the participants experienced an increase in eye secretions at the beginning of their illness.

The coronavirus that causes COVID-19 primarily travels through droplets in the air. These droplets occur when somebody who has the virus sneezes, speaks, or coughs. When you breathe in these droplets, the virus enters your body and can replicate.

You can also contract the virus if you touch surfaces that the droplets may have landed on, such as tables or handrails, and then touch your eyes, nose, or mouth.

It’s suspected that the virus can also be transmitted through the eyes.

The virus responsible for the 2003 SARS outbreak is genetically similar to the coronavirus that causes COVID-19. Research on this outbreak found that a lack of eye protection put healthcare workers in Toronto at risk of contracting the virus.

The same research suggests that the risk of transmission through your eyes is relatively low compared to other means. However, taking precautions to protect your eyes is likely still a good idea.

Scientific knowledge of COVID-19 is rapidly evolving, and it’s possible that future studies will find the risk is higher than originally thought.

How COVID-19 gets into to your eyes

The virus that led to the 2003 SARS outbreak entered the body through an enzyme called angiotensin converting enzyme 2 (ACE2). Research has also found that the virus that causes COVID-19 also likely does the same.

ACE2 is widely found in places throughout your body, including your heart, kidney, intestines, and lungs. ACE2 has also been detected in the human retina and the thin tissue that lines your eye.

The virus enters human cells by tricking cells into thinking that it’s ACE2.

The virus can attach to a cell at a particular spot, called a receptor, where ACE2 fits exactly. The virus mimics the shape of the ACE2 enzyme well enough that the cell allows the virus to enter it, same as it would the enzyme.

Once in the cell, the virus is protected and can replicate until it ruptures the cell. Copies of the virus find new cells to invade, repeating the process.

When the virus reaches your eyes, it may cause pink eye or other eye symptoms.

Protecting your eyes from airborne respiratory droplets may help reduce your chances of developing COVID-19.

You can protect your eyes by:

  • switching from contact lenses to glasses to help prevent contact with your eyes
  • wearing glasses or sunglasses to partially shield your eyes from the virus
  • not rubbing your eyes
  • following other recommended practices such as washing your hands, avoiding touching your face, avoiding contact with sick people and social distancing, and wearing a mask in public

Having pink eye or irritated eyes doesn’t mean you have COVID-19.

There are many other reasons your eyes might be red or swollen, including allergies, getting foreign objects in your eyes, and digital eyestrain. Eye-related symptoms are rare for people at the beginning of COVID-19.

So far, there haven’t been any reports of sight-threatening symptoms of COVID-19, so it’s most likely that your eye symptoms will be mild. A doctor may be able to recommend specific ways to manage your symptoms, such as eye drops.

To reduce the transmission of COVID-19, it’s a good idea to get in touch with a doctor by phone or video appointment instead of going to a clinic. If you have COVID-19, you may transmit the illness to others at a clinic or hospital.

To reduce the risk of transmitting COVID-19 to other people, including healthcare workers, it’s a good idea to avoid going to a hospital if your symptoms are mild. About 80 percent of people with COVID-19 have mild symptoms.

Many clinics are offering virtual visits, which involve talking to a doctor either by phone or online. These services lower your chances of transmitting the disease and are a better option than visiting a doctor’s office, unless your symptoms are severe.

Medical emergency

If you or a loved one has any of the following emergency symptoms, you should get in contact with a medical professional right away:

  • trouble breathing
  • chest pain
  • blue lips or face
  • confusion
  • inability to wake

Some people with COVID-19 develop pink eye, but it’s not as common as other symptoms like fever, dry cough, and fatigue. Research has also found it seems to be a more common symptom in people with severe cases of COVID-19.

Minimizing contact with your eyes and taking other precautions like wearing a face mask in public, washing your hands frequently, and practicing social distancing can help you reduce your chances of developing COVID-19 or pink eye.