You are not the only person complaining of pain behind the eye. There is a lot of solar radiation coming through. People on youtube are measuring extreme UV. That can inflame you brainstem and/or your sphenoid sinus. Why? Those are unprotected regions. To prove this is inflamation, take aggressive approach with ice. Use clear gallon zip lock, crushed ice is best. Alternate between eye and neck. If it ais n exacerbation by radiation the pain will go away in about ten minutes if not sooner. If the pain persists, snuffling is by far the best way to clear out your sinuses. Do this with warm water.