The eyes have it

6th century coptic eyes, in the British Museum (and that's the knot of evil, underneath). The National Gallery has 14th century Italian eyes doing much the same kind of looking, in a painting by Jacopo Cione (or maybe someone else; I should have written it down) - which isn't to be found on the net, so here's a crowd scene by his brother Nardo
which doesn't have quite the same strangely furtive, suspicious feel.

Addendum, December 2016
Returning to this post nearly 10 years later, I find plenty of information on Jacopo di Cione online and also some possibilities for the painting seen in 2007, which I can't remember exactly -

Detail from The Ascenscion (via)

Detail from the San Pier Maggiore Altarpiece 1370-1371 (via)

On the National Gallery's website, eg here, you can zoom in to various sections of the image.

Nardo collaborated with another Cione brother, Orcagna, on the frescos in the Strozzi chapel of Santa Maria Novella in Florence, for instance on this Last Judgment -

This site looks a bit ropey ("online since 1996") but clicking on the thumbnails gives good details. Hell is particularly impressive - but without any of the covert glances seen elsewhere.

It's all a long way from 6th century Ethiopia!