omicra

It must be remembered that we are dealing with uncials. ΒΟΟ could not very well become ΒΟΥ. But in the pre-Euclidean alphabet the impure diphthong resulting from the contraction of two omicra, as distinguished from the pure diphthong with a real u-element, was written Ο.

Perhaps the announcers think that two omicra make one omega, for, of course, unlike the other words I have quoted, “polio” does have two omicra in it.