Continuity mistake: Near the end, when Frank Langella performs the (flawed) satanic ritual, he pours a ring of gasoline and ignites it, then kneels down to pass his hands through the fire. They digitally inserted the reflection of the fire ring in his eyeglasses for about 10 seconds. Thereafter, his glasses do not reflect the flames, even after he douses himself with gasoline and self-immolates.
Charles Austin Miller
1st Mar 2016