safek berachah l'hakel

every morning we say a blessing ... pokeach Ivrim, (... open eyes of the blind). there is a question if a blind person should recite this blessing.

There is a difference of opinions: one say should not say it, some say he should. There is a rule safek beracha l'hakel (if there is a doubt or disagreement regarding a rabbinically instituted blessing, the blessing should not be said). However, the opinion of the the Arizal is that everyone says all the blessings and we do not use safek beracha ... against the Arial.

btw, the same argument goes for deaf person and noten l'sichvei (when we hear rooster in the morning)