Dr Anthony Fauci has suggested that eyewear such as goggles or face shields can offer more complete protection from the virus that causes COVID-19 than covering the nose and mouth alone. Although stopping short of a universal recommendation, Fauci advocates eyewear for those who want “perfect protection of the mucosal surfaces,” including the eyes. For the general public, eye protection is optional but could serve as an effective means to reduce the risk for COVID-19, depending on the environment.
It’s a different story for healthcare providers (HCPs) in many clinical settings, where eye protection recommendations depend on the likelihood of exposure in the direct care of patients. In its updated guidance, Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic, the Centers for Disease Control and Prevention (CDC) recommends eye protection for the following HCPs:
Those caring for patients with suspected or confirmed SARS-CoV-2 infection; and
Those working in facilities located in areas with moderate to substantial community transmission who are more likely to encounter asymptomatic or presymptomatic patients with SARS-CoV-2 infection.
In addition to wearing a mask when caring for a patient with suspected or confirmed COVID-19, the CDC recommends goggles or a face shield that covers the front and sides of the face, rather than safety glasses or standard prescription eyeglasses, which, by design, offer limited protection from splashes, sprays, and airborne particles.
The CDC doesn’t address the risk for infection with SARS-CoV-2 from coworkers or the general public beyond these two clinical scenarios, leaving HCPs to decide for themselves whether and what type of eye protection they should wear at or outside the workplace and the potential benefits of doing so.
Why Worry About the Eyes?
Given that COVID-19 cases and deaths continue to climb, it’s clear that we don’t perfectly understand all modes of transmission, including the role of the eyes.
The eye, like the nose and mouth, is a mucous membrane that might serve as a portal for acquisition of SARS-CoV-2 by providing a large surface area exposed to droplets or airborne particles and contamination from a person’s hands. The surface of the eye is thought to contain SARS-CoV-2 ACE receptors, which bind to the virus. The virus has been isolated in tears and other conjunctival secretions, and like other viruses, it can be carried down via the nasal-lacrimal duct into the nasopharynx and into the lungs. Moreover, conjunctivitis can be the presenting sign of COVID-19.
Which of the many available eyewear options significantly reduce the risk for viral transmission? Let’s review the evidence.
Early in the pandemic, doctors in China made a curious observation about COVID-19 patients admitted to their intensive care unit. Very few of these patients routinely wore prescription eyeglasses, suggesting that glasses might have a role in protecting the wearer from the virus that causes COVID-19. Their observations were confirmed in a cohort study of patients admitted to the hospital with a diagnosis of COVID-19. Inpatients with COVID-19 were significantly less likely than the general population (5.8% vs 31.5%, respectively) to wear glasses for at least 8 hours daily.
This significant disparity suggests a protective effect of full-time eyeglass wear against the acquisition of SARS-CoV-2, possibly by serving as a barrier to droplet and ocular surface transmission if worn when directly interacting with others. The findings of this small study, while certainly intriguing, are far from conclusive, and a prospective study would be needed to prove that glasses can guard against COVID-19.
Standard eyeglasses protect only the front of the eye, so airborne viruses, droplets, or splashes can reach the eyes from the top, bottom, or sides of the glasses. Poorly fitting or loose glasses might encourage more handling of eyewear, with potential contamination from the wearer’s hands.
Like standard eyeglasses, safety glasses (also known as trauma glasses) provide a relatively low level of protection against respiratory droplets. Safety glasses are primarily designed to protect the wearer from high-velocity impact and exposure to radiation and chemicals. The American National Standards Institute (ANSI) regulates the standards for this type of eyewear, with ANSI Z87.1 being the standard rating for eye and face protection. Note, however, that this rating does not include protection against bloodborne pathogens or other types of infection control.
Like prescription eyeglasses, many safety glasses are designed with gaps between the frame and the face, which may fail to block transmission of infection through sprays, splashes, or airborne particles circulating in poorly ventilated environments. This exposure point can be minimized with side shields or a wraparound design.
Plano safety glasses can be worn over prescription glasses and will probably provide some protection. Some safety glasses can be customized with prescription lenses to eliminate the need for multiple pieces of eyewear.
By creating a seal around the eyes, goggles can dramatically reduce the access of the virus to the ocular surface by offering protection against sprays or splashes of respiratory droplets.
This effectiveness may depend on the style of the goggles. Goggles are available with different degrees of ventilation, which cuts down on fogging. Direct-vented goggles allow unimpeded airflow and also may allow penetration by sprays and splashes. Indirect-vented goggles may block liquid splashes but could still allow small airborne particles to penetrate. Nonvented goggles offer the highest level of infection by blocking airborne particles as well as sprays or splashes.
Some goggles can fit over prescription glasses, but it is important to check for any gaps between the edge of the goggles and the face.
Goggles are currently recommended for providers interacting with COVID-19 patients or working in areas with moderate to substantial SARS-CoV-2 transmission. Typically a nondisposable item, goggles should be removed after leaving an infected patient’s room, and cleaned and disinfected prior to next use. In areas with minimal or no community spread, goggles are considered optional unless otherwise indicated.
Unvented goggles (along with a face mask) would probably also offer the highest level of protection for anyone spending a long period of time with people in a poorly ventilated environment.
Face shields may be worn in conjunction with or as an alternative to eyeglasses, safety glasses, or goggles. Face shields worn with goggles provide the maximum level of eye protection. By themselves, face shields mainly block direct droplet sprays.
Face shields reduce exposure of the mucous membranes, including those of the eyes, mouth, and nose, to the virus. To provide optimal eye protection from viral transmission, face shields should cover the crown and chin and extend to the ears.
Face shields are considered an appropriate form of eye protection in areas with moderate to substantial SARS-CoV-2 transmission.
Questions have been raised about whether contact lenses can act as a shield against the transmission of SARS-CoV-2. On the flipside, there are fears that contact lenses could serve as reservoirs for the virus. Contact lenses could also…