These two additional and unusual variants are presumably of the Third Intermediate Period. See1 for other dated ones of all periods

Openwork blue glaze flat back, partly broken Wedjat eye

Openwork blue glaze flat back, partly broken W 6.1 Eton College Museum #ECM.1683-2010

Openwork blue/black/green/white glaze flat back Wedjat eye

Openwork blue/black/green/white glaze flat back W 6.6, H 5.0 Eton College Museum #ECM.842-2010

Reference

1Müller-Winkler C. Die ägyptischen Objekt-Amulette: mit Publikation der Sammlung des Biblischen Instituts der Universität Freiburg, Schweiz, 1988. Vandenhoeck and Ruprecht, pp. 252-267 and nos. 9-239