Istace,
I only deal with being near sighted and astigmatism, but I had gotten to the point I could not thread the needle on my old sewing machine. I had to take the needle out, hold it 3 inches in front of my face (without glasses), then put the threaded needle back in the machine, hoping I did not twist the thread around it as I went.
I have the little bird needle threader and I use it when I am doing EPP. I also have one of these gizmos
https://singer-featherweight.com/blo...eedle-threader It works very well for threading my sewing machine.
However, as you are dealing with serious vision impairment, please try out as many LA machines as you can and if possible find a place that will rent you time on a machine before taking the plunge.