Super Bowl Champ: NFL Made Me Deaf ... 11 Concussions

He won TWO Super Bowl rings with the Raiders -- but ex-NFL safety Mike Davis says his NFL career cost him his hearing ... a result of at least 11 CONCUSSIONS.

Davis -- who still rocks his rings from Super Bowl XV and XVIII -- was at the Chris Aire jewelry boutique this week when he told us he suffers from total deafness, vertigo, blurred vision and more.

The 59-year-old says he recently went back to the Raiders to pull his team medical records -- and the team had listed 11 concussions that he didn't know he had.

Davis says he knew he got banged around on the field -- but never thought the damage was as serious as it was.

Question is ... what does Davis want the NFL to do about it now? Check out the video.