Have you read the whole Isaiah 42 and 43? These chapters speak also who blind and deaf (spiritually) God's servant is? But then it does not of course refer on Jesus. But on Israel or the spiritual Israel, those who Jehovah calls his witnesses.
18 Hear, YOU deaf ones; and look forth to see, YOU blind ones. 19 Who is blind, if not my servant, and who is deaf as my messenger whom I send? Who is blind as the one rewarded, or blind as the servant of Jehovah? 20 It was a case of seeing many things, but you did not keep watching. It was a case of opening the ears, but you did not keep listening. -Isaiah 42:18-20
8 “Bring forth a people blind though eyes themselves exist, and the ones deaf though they have ears. -Isaiah 43:8
O Israel. 23 You have not brought me the sheep of your whole burnt offerings, and with your sacrifices you have not glorified me. I have not compelled you to serve me with a gift, nor have I made you weary with frankincense. 24 For me you have bought no [sweet] cane with any money; and with the fat of your sacrifices you have not saturated me. In reality you have compelled me to serve because of your sins; you have made me weary with your errors. -Isaiah 43:22-24
Sad to point to the facts, but the name Jehovah's witnesses is taken from a bad context. But it also fits them according to the context. How could they take the name Jehovah's witnesses, when it is in a such negative context? Well as Isaiah says, they are blind and deaf, so that should be the explanation.