Good, I will be praying all goes well. Please, keep us updated on things.
God Bless
Have you contacted the National Federation of the Blind of Texas. You can Google it or call them, (817) 274-7119. I think they may be able to assist with some of your needs, at least with the cost of the test that needs done.
I will be praying for your son and your family.
God Bless & uphold you through this difficult time.