You would sort out people at higher risk and lower risk, and then maybe don't have to examine those at low risk as much. You will have a natural (method) of sorting out people for prevention, rather than for treatment.

But if you brought the lenses away from the top of the surface, you lost the image. They were not a practical way to find tiny early changes.

Most of these early changes probably don't go anywhere. But we are looking for ways to differentiate between good apples and bad apples.

I think for people who were not convinced of the risk, this provides further evidence.

Everyone who has been identified as a close contact has been treated. Those people who are at risk are household contacts, like roommates or people who come in close contact with the person through kissing or sharing of food or drink.

Most people would rather be certain they're miserable, than risk being happy.