The Wisdom of Mimir

To cast this spell, you must cut out an eye and throw it into a pool of water along with chants and hand movements. Once the spell is cast, a magical spectral well will appear in front of you. If you wish to use this spell, you must use the drinking horn and drink a horn full of the ghostly water inside the well. If you do this, you automatically succeed on all wisdom checks except ones that involve seeing, which then you must regularly roll for (hence the lost eye). However, you do not get a disadvantage. At level 17, you may allow other creatures to gain this bonus.