Tonometry for measuring IOP may ba potential pathway for virus, disease transmission

"The cornea is like an elastic surface. So, as it deforms and as it recovers its shape, it gives the eye an additional kick," said author Saptarshi Basu. "It's a capillary wave merged with this corneal deflection, which gives rise to a consolidated wave, and that is what makes the tear fluid expand and go out."

The waves moving within the eye and tear liquid eventually become unstable, and the tears break up into droplets. The team tracked the speed of those droplets as they left the eye and predicted they could travel up to a meter away from the patient. The distance depends on the air flow within the room.

Eyes with more tears created more droplets than dry eyes. The scientists recommend not using eye drops before the glaucoma test unless medically necessary.

"It is not just limited to SARS-CoV-2. It can be extrapolated to other types of pathogens as well," said Basu. "What you think is a very safe, noncontact procedure, even then, one needs to be a little careful."

This work can help eye care practitioners to develop and follow health and safety protocols, like improved room ventilation and cleaning nearby instruments and surfaces, that may not have been considered necessary in the past.