As many players recently have asked us how to handle a glowing eyes VFX ICly in game, the DM team has decided the following guideline:
No mask, hood, or helmet can prevent glowing eyes from being seen ICly. If you only notice a faint sparkling over the PC's head, within their hat, or otherwise misplaced, you can presume that you also see glowing eyes from said PC. Even if the VFX is nullified, however, it is presumed that light is still emitted from any eye holes that allow vision, and players who have PCs with the associated VFX should make it clear via their description and/or emotes.