there is the part on the rift face mark that rubs the glasses and squeezes the glasses against the head making glasses very uncomfortable.
so i took a small crafting hacksaw, and some pliers and depending on your skill you wont need anything but the small hacksaw, and some scissors to trim the thin plastic.
trim the thin plastic using the house scissors, then the hard plastic is trimmed by the hacksaw. wear some gloves in case you hand slips. and dont be too rough or the face mask might snap in two. you want to trim enough off the glasses can wiggle comfortably when you wear them in the rift, trim both sides of the face mask;