"...signed and dated 1449 by Petrus Christus, the leading painter in Bruges (Flanders) after the death of Jan van Eyck. (http://www.metmuseum.org/collection/the-collection-online/search/459052) Insofar as portraits were concerned, Christus was no van Eyck. His male heads in [this painting] show a penchant for rendering both eyes approximately identical in size and shape, thus distorting the shape of the cheekbones and upper part of the head (this error persists even today among amateur artists). It's unknown if Christus traveled to Italy at some point, or if linear perspective filtered north to his workshop, but Petrus Christus is credited by most art historians as having brought an understanding of the rules of perspective to the Netherlandish artists of the Northern Renaissance about 1450. It's hard to pinpoint an exact date for such a breakthrough, though we can see it suddenly appear in his works such as... (http://art-now-and-then.blogspot.nl/2017/02/petrus-christus.html)