Glare comes from the ocular then? So could winged eye cups not eradicate this.
I'm not an expert but IME eye shields will sometimes help with "glare" but not will not eliminate it. Strictly speaking eye shields don't eliminate glare. But it seems to me glare occurs in some lighting conditions which also cause reflections off the oculars which causes additional image degradation. The eye shields eliminate that part of the problem in those situations.
Mike