As someone who is or became blind, it might have happened for a number of reasons, and this could have been your choice or a choice that was made for you. To determine how this happened to you, you can roll on the table below or choose with what has been provided.

Since you've become blind, you've learned how to use your blindsight. As a creature with blindsight, you can perceive your surroundings without relying on your sight, within a particular radius. Normally, creatures without eyes have learned this sense, but you have learned it too. With your blindsight, you use your heightened senses to perceive the world - your senses change based on how long you have been blind combined with the time you've spent in the world.

• At 1st level, your sense of hearing has a radius of 60ft (centred on you).
• At 1st level, your sense of smell has a radius of 30ft (centred on you).
• At 4th level, you gain your tremorsense, and it has a radius of a 30ft (centred on you).
• At 6th level, your sense of hearing and smell are increased by 20ft.
• The range of your taste and touch remain at 5ft, regardless of your level.
• At 8th level, you can sense another creatures heartbeat if they are within 5ft of you. You can make Insight checks on these creatures with advantage.
• At 12th level, your tremorsense is increased to a radius of 60ft.
• At 16th level, your sense of hearing and smell are increased by another 40ft.

Since you are permanently Blinded, you have these characteristics:

• You can not be blinded by any effect. 
• You are not affected by spells such as Hypnotic Pattern, as they need to be seen to take effect.
• You have a permanent advantage on Perception and Investigation checks when you use your senses that don't rely on sight and they are within your range.
• You have advantage when rolling against Intimidation or Deception that are reliant on sight.
• You are proficient in all Wisdom-based skill checks and saving throws.
• If you would attack a creature within your blindsight range, you would not have disadvantage on the attack (as a result of your blinded condition).
• If you would be attacked by a creature within your blindsight range, they would not have advantage on the attack (as a result of your blinded condition). 

In combat, you can be made vulnerable, and have these characteristics:

• If you would be Deafened, your blindsight would be reduced to 0. In addition, any creature would have advantage on attacks made on you, and you would have disadvantage on attacks you would make.
• Any ranged attacks and spells you would make beyond your blindsight range would have disadvantage. Any creatures that would attack you beyond this radius have advantage.
• You fail all checks that are reliant on sight.
• You have disadvantage on Investigation, Stealth and Sleight of Hand checks that are reliant on sight.
• You have disadvantage on any Dexterity saving throws if the source is out of your blindsight range. (e.g. a Fireball being cast from 150ft).