Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 118.42; Flight Crew Total 8570.50; Flight Crew Type 3353.82
Confusion; Distraction; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
General None Reported / Taken
Company Policy; Environment - Non Weather Related; Human Factors
As I was leaving the flight deck approximately 6.5 hours into the flight for my break the Captain informed me the Purser had spoken to him about mask usage on the flight deck.  Upon returning from my break I was informed there was further conversation with the flight attendants.  Not much detail was discussed as we began the preparation for descent into ZZZ.  I never spoke to any FAs about the issue nor did they speak to me about it.I am aware the Captain chose not to wear a mask for safety of flight reasons concerning his glasses while on the flight deck.
Air carrier First Officer reported the Captain chose not to wear a mask for safety of flight concerns while wearing glasses.