Some who are born blind end up joining a monastery to learn to adapt to being blind. Some are able to attune to their other 4 senses so well that their blindness is not so much as a negative, but a gift. They also have learned to expertly control their own Ki and read the Ki of others to negate the negatives of being blind. These are the Blind Monks.

It is not required to be naturally blind to have been taught this tradition, however those who are not blind and have followed this tradition went through their training with a blindfold on. In order to make use of any of these abilities you must be blind. If you use a blindfold, you must spend 1 hour after applying the blindfold to regain you bearings.  Or you may voluntarily remove sight from your character, making them permanently blind unless sight is recovered through magical means.

Enhanced Senses

Starting when you choose this tradition at 3rd level, you have decided to lose your sight in an attempt to gain the benefits of honing your other senses. You lose your other means of sight and gain blindsight or tremorsense to a range 5 feet. This blindsight/tremorsense has limits, however and can only passively sense up to your passive perception. Your blindsight/tremorsense increases by another 5 feet when you reach 6th, 11th, and 17th level.

You gain proficiency with the perception skill, or if you are already proficient with perception you gain expertise with perception.

Blindsight

You gain blindsight up to 5ft, this increases by 5ft for level 6, 11, and 17.  Total of 20ft of Blindsight at 17th level.

Tremorsense

You gain tremorsense of 5ft, increasing by 5ft at levels 6, 11, and 17. Total of 20ft of tremorsense at 17th level.

Lie Detector

When you reach level 6 you gain the ability to tell if someone you are talking is lying through sensing their heartbeat, if they have a heart that is still beating.  You gain proficiency with the insight skill, or expertise if you already have proficiency in the insight skill.  You can use 1 ki point to gain advantage on insight checks for 10 minutes on the creature you wish to insight check, so that you can focus more on the creatures heartbeat to sense if they are lying or telling the truth.

Counter

You gain the ability to react a hostile creature's attempt to attack.  As a reaction you can spend 1 ki point to impose disadvantage on the first attack that is targeted at your character, if the attack misses you can use your reaction to attack the creature that tried to attack you, you may spend 1 ki point to use the Stunning Strike feature for this attack as well.  If the attack is from a ranged weapon, you can roll a perception check vs the creatures stealth check to see if you can impose this disadvantage, if a creature misses with this disadvantage applied you can use the Deflect Missiles feature to expend 1 ki point to make a ranged weapon attack with proficiency, regardless of your weapon proficiencies, and the missile counts as a monk weapon for the attack, which has a normal range of 20 feet and a long range of 60 feet.

Perfected Senses

At 17th level you gain tremorsense or blindsight, which ever you didn't choose at 3rd in this subclass, equal to your current blindsight/tremorsense, the one you chose at 3rd level in this subclass, you blindsight and tremorsense are also doubled.  The only way you cant any vision is if you are deafened and not touching any ground, or if the target for any attack is on a separated ground, ie. you are one side of a ravine the target is on the opposite side.  You can expend 3 ki points to make an unarmed strike, this can be apart of the attack action, flurry of blows or ki-fueled strike, called Thunder Clap.

Thunder Clap

You can expend 10 ki points to replace an unarmed strike, this can be apart of the attack action, flurry of blows or ki-fueled strike, called Thunder Clap.  Using your knowledge of vibrations, specifically soundwaves, and your power to manipulate ki you can increase the sound at which you can create to deadly levels.  You expend 10 ki points to use this ability as apart of you attack action, bonus action or flurry of blows.  If the creature cannot hear or is deafened it automatically saves the Constitution saving throw.  The DC equals your Ki save DC.  On a failed save, the creature takes 10d10 thunder damage and fall unconscious.  On a successful save the creature takes half the amount of thunder damage and don't fall unconscious.  This can only be used once per turn.