Monks who trained themselves very highly can fight without sight.

Blind Sense

When you choose this tradition at 3rd level, you gain the following abilities.

Blindsight - You can perceive your surrounds without relying on sight, within 15 ft.

Tremorsense - You can detect and pinpoint the origins of vibrations within 15 ft, provided that the creature and the vibration are on in contact with the same ground or substance.

Alert - You gain the Alert feat.

At level 6th, your Blindsight and Tremorsense have 30 ft range, and 60 ft at level 11th. You treat your blindness as normal outside of this radius.

Sonic Wave

At 6th level, you gain the ability to channel your ki into sonic waves of energy. You gain a ranged attack which you can use with the Attack action. The attack has a range of your blindsight. You are proficient with it, and you add your Dexterity modifier to its attack and damage rolls. It deals a amount of bludgeoning damage equal to your Marital Arts die, as shown on the Monk table. Also you can use stunning strike by this special attack.

When you use the attack action on your turn to use this special attack, you can spend 1 ki point to make two additional attacks with it as a bonus action.

Successful sonic wave attacks on target creatures or objects leave a mark of energy for 1 minute. You can spend 1 ki point to cast the misty step as a free action to teleport next to a marked target in unoccupied space. You add your Wisdom modifier to the damage rolls against marked targets.

Tempest

At 11th level, you gain the ability to use your attack action spending 3 ki points to smash the ground creating a small seismic seizure within 30 ft. Each creature in that 30 foot radius must succeed on a Dexterity saving throw or take 3d6 bludgeoning damage.

Targets who fail the saving throw become marked and can be seen by you with truesight until the start of your next round.

You can increase the power of Tempest by spending ki points. Each point of ki you spend, up to a maximum of 3, increases the damage by 2d6.

Sixth Sense

At 17th level, you can sense the intentions and the weakness of a target creature with a heartbeat in your blindsight range. You gain advantage in all your attack against marked targets.

Additionally, when you hit a marked creature with an unarmed strike or a sonic wave, you can spend 3 ki points to add an imperceptible vibration which causes 3d10 bludgeoning damage. If critical hit, you may restore 3 ki points.