Temple Removal is a common technique used by animators when drawing glasses viewed from the side. In order to show a character's entire eye, part of the glasses' temples (the parts that go over the ears), hinges, or end pieces are not drawn, even though they would normally obstruct the eye.
Though often mistaken for QUALITY, temple removal is usually a purposeful, stylistic animation decision rather than an error.
Gallery[]
Manjoume Fumi in Aoi Hana
Arima Kousei in "Shigatsu wa Kimi no Uso"