The Eyes are a Gateway for COVID-19: Safety Eyewear Can Help
Because the coronavirus infects us through the eyes, nose and mouth, proper PPE has become one of the most important tools during this pandemic. It’s crucial to pick the right eyewear for your safety.
- By Mary Padron
- Jun 01, 2020
The novel coronavirus, which causes the disease COVID-19, is believed to spread among people in three ways. According to the Centers for Disease Control and Prevention (CDC), the virus spreads:
1. From close contact with people who have it.
2. From respiratory droplets that become airborne when someone, who is infected, sneezes or coughs nearby.
3. From touching our mouths, noses or eyes after touching a surface that has the virus on it.
The CDC says that “infectious agents are introduced to the eye either directly (e.g., blood splashes, respiratory droplets generated during coughing or suctioning) or from touching the eyes with contaminated fingers or other objects.”
Because our mouths, noses and eyes are gateways for the virus to enter, certain products in the Personal Protective Equipment (PPE) realm have taken center stage, especially N95 respirators and surgical face masks since they provide a barrier to respiratory droplets entering the mouth and nose. However, the CDC reminds us that eye protection is equally important and “provides a barrier to infectious materials entering the eye and is often used in conjunction with other PPE such as gloves, gowns, masks, or respirators.”
This article will discuss:
- Some of the fogging challenges that arise from wearing masks and safety eyewear together.
- Vision protection options for infection control, including goggles and face shields.
The Top Eyewear Complaint—Fogged Eyewear—Is Now Bigger Than Ever
One of the eye protection challenges surging during the pandemic is fogged eyewear. Essential industrial workers, who often wear ANSI Z87.1 impact resistant safety glasses, are experiencing increased fogging issues from having to wear masks and safety glasses together during the COVID-19 pandemic. The general population is wrestling with fogging concerns too as they wear DIY face coverings and glasses when they go to the grocery store.
Many PPE manufacturers offer safety glasses and goggles with anti-fog coatings1 that are either water-based (hydrophilic) or solvent-based (hydrophobic).
Both water- and solvent-based products are effective at preventing fogging; however, lab testing shows that the thicker, water-based coating2 will last up to ten times longer in high humidity environments (up to 80C or 176F). Because the water-based coating is thicker, it can withstand cleaning significantly longer and does not easily rub off like some solvent-based anti-fog coatings.
Water is also environmentally friendly and entirely safe. Solvents have toxic properties, can be flammable and can have a negative impact on the natural environment. Water-based coatings are non-flammable and non-toxic.
Anti-fog coatings are offered in a variety of lens colors including clear, smoke, indoor-outdoor and amber to satisfy various needs of the industrial workforce.
Vision Protection Options for Infection Control
The ANSI Z87.1 standard delineates between primary protection, secondary protection, and face shields. The ANSI definitions for these categories are:
- Primary protection – A device that may be worn alone or in conjunction with a secondary protector
- Secondary protection – A device that shall be worn only in conjunction with a primary protector
- Face shield – A protective device commonly worn to shield the wearer's face, or portions thereof in addition to the eyes, from certain hazards. Face shields are secondary protection and shall be used only in conjunction with primary protection.
Although ANZI Z87.1 impact resistant safety glasses are appropriate in an industrial setting, they are not typically used for infection control because they do not provide adequate splash or droplet protection.
However, during the pandemic with its subsequent shortages of goggles and face shields, many PPE manufacturers have seen additional requests for safety eyewear with frameless wraparound lenses, foam-lined eyewear, flex side shields and over-the-glass (OTG) styles that go over prescription eyewear.
Indirectly Vented Goggles with Anti-fog Coating
Goggles are a key PPE item for eye protection, and they play a critical role in infection control.
Goggles that are close-fitting and indirectly vented with a manufacturer’s anti-fog coating provide reliable and practical eye protection against splashes, sprays and respiratory droplets. The three primary types of goggles include:
- Direct vented goggles allow the direct flow of air into the goggle and may allow penetration by splashes or spray.
- Indirect vented goggles limit or prevent the passage of liquid splash into the goggle.
- Non-vented goggles do not have venting and prevent the passage of dust, mist, liquid and vapors.
For infection control, indirectly vented goggles or non-vented goggles are the preferred PPE.
Most safety goggles are offered with anti-fog coatings and are sized to fit over prescription glasses. They protect against 99.9 percent of harmful UV rays and have a hard coat polycarbonate lens to protect against scratches. Although they provide vision protection, they do not offer spray or splash protection to the other parts of the face. That is where the face shield comes into play.
Face Shields and Their Role in Infection Control
According to the CDC, “Healthcare workers' faces have been reported to be the body part most commonly contaminated by splashes, sprays and spatter of body fluids.”
A face shield provides barrier protection to the facial area and related mucous membranes (eyes, nose and lips). Because face shields are considered secondary protection, they should be worn in conjunction with other PPE like goggles, surgical masks and N95 respirators, which sometimes can help extend the life of those PPE items.
Despite its secondary protection status, face shields offer many significant advantages compared to other forms of face/eye protection used in healthcare and related fields. Some of the key advantages of face shields are:
- more comfortable
- protects a larger portion of the face
- less fogging than goggles
- less claustrophobic
- no impact on breathing resistance
- no fit testing required
- can be disinfected easily
- wearers do not need to be clean shaven
- easy to don and doff
- easier to communicate with others
- prevent people from touching their faces
Choosing the appropriate face shield for infection control is dependent upon:
- The current available knowledge, which can change quickly during a pandemic
- The task to be performed
- The risk associated with the task or procedure
- other PPE used in conjunction with the face shield
- personal vision needs
The CDC has recommendations on how face shields can provide improved protection from infectious agents:
“To provide better face and eye protection from splashes and sprays, a face shield should have crown and chin protection and wrap around the face to the point of the ear, which reduces the likelihood that a splash could go around the edge of the shield and reach the eyes. Disposable face shields for medical personnel made of light weight films that are attached to a surgical mask or fit loosely around the face should not be relied upon as optimal protection.”
The importance of face shields for infection control among medical professionals is gaining steam during the pandemic as many health care facilities are now requiring their employees to wear face shields full time to prevent the spread of the virus. The discussion3 is rapidly evolving to whether the general public should also wear face shields in everyday life to help flatten the curve.
Face shields are gaining favor4 because they can be made quickly with materials that are easy to obtain. Plus, with the shortage of N95 respirators and surgical face masks during the pandemic, the CDC has recommended the use of face shields if masks are unavailable.
One thing we have been reminded of during the COVID-19 pandemic is that we really do not know what is next. However, we are also learning that “together, we can get through this.” The private sector, including PPE and non-PPE manufacturers, have been helping tremendously during the pandemic, remobilizing their operations teams and supply chains to create in-demand pandemic PPE. The world will grow and learn from this, and I think we can agree that PPE has a defining role in making the world a safer place.
This article originally appeared in the June 2020 issue of Occupational Health & Safety.