The glasses work. It's an inconvenient solution to Sadde's disability, they'll have to take the glasses off to use the Sight instead of just refocusing their eyes, but there's no danger of spontaneous total existence failure.
They have time to draft a seal tight enough to be worth using and simple enough that as many Others as possible can understand it, and run the result by Johannes. And then there's the unexpected obstacle of finding things to use it on. The next council meeting provides a possible target. In the among the background noise issues that no one actually cares about but everyone examines responses to, there are reports of animals turning up in various stages of digestion. Since that's not a thing that happens naturally it's clearly worth mentioning here, but it doesn't impinge on the interests of anyone here so they note the existence of an unknown Other and move on.