I was just wondering if it was an aspergillus infection, yeast or some other problem. It seems like asper is prone to causing voice changes along with surprising high weight loss and apparently fast onset. Never heard of it causing blindness or stroke through. Unless a chunk of a fungus colony broke off and got lodged somewhere. I've heard asper is quite difficult to treat unless they have come up with better meds recently. I knew of a blue front several years ago that nearly died of it. The owner was going through a hard time and stopped weighing his bird for a while. When he finally got around to it again he was shocked at how much she had lost. He promptly got the bird to the vet to start treatment but it was already quite advanced. Many trips back and forth from the vet hospital to scope and monitor progress. The bird lived but it was 6 months or more of intensive treatment.