I have encountered and interacted with a few occasionally and by and large the 'handicapped' are not necessarily disabled by any stretch of the imagination.
It is said that lacking any of the five basic senses is compensated by additional acutiy of those which remain.
I have seen evidence of this for myself. My dear grandma Sallie who was functionally deaf could get all manner of conversations correctly til I was the one left dumbfounded.
I have encountered other individuals as well who could take me to task in an instant with intellects and abilities that surpass my own by a long shot.
I feel that something interstitial and compensatory within the person is enabling these skills which I find absent in myself.
Today brings us the relatively new International Day of Sign Languages.
It is celebrated internationally each September 23rd as a function of the International Week of the Deaf.
The date of this event is that which the World Federation of the Deaf was established well before my time in 1951.