i had my first sxperience with iritis 3 years ago, my doctors felt it was caused by a severe strep throat infection i had 1 week prior. I to had vison loss, and my iritis continued for three months. i am happy to say , my vision has since totally returned back to normal. I am also happy to say that i have not since suffered with iritis since then. Although my doctors say it could only be a matter of time. there is great hope for your sister, just continue to support her, and encourage her to do as her doctor instructs her to do. good luck, kym.