In 3rd grade I was diagnosed as borderline dyslexic. I now teach algebra & geometry in high school. I have always found it very easy to write backwards, to read upside down, and to write upside down. I used to play tricks on my husband when he was in the navy by writing him letters backwards. It comes very natural to me. This is an interesting discussion, with the exception of the ones here who are so "close minded" to trying something new.
I only read one of my assigned novels in high school. I read Jane Eyre, only because the teacher was patient, gave me extra time and was willing to work with me. My 3rd grade teacher, yelled at me for reading the wrong words. I made it through high school and college by using the short stories and synopsis. My spelling is atrocious. I have a word book that I carry everywhere with me, and share with my students, it is nothing but words, no definitions, just words. I had to figure out what helped me to get through school and I now try to share that with others.
I've had several SPED teachers in the 3 different schools admit to me that most of their courses were about ADD, ADHD and others, but little was taught about dyslexia. I've actually had one or two come to me and ask for suggestions about what they might try to do to help their dyslexic student. (I do not hide my dyslexia, I share it with my students, and fellow teachers.)
I use nothing but colored paper in my classroom, because white with black text is such a severe contrast that the letters feel like they are in motion. I have colored transparencies that I keep by my bed to read novels.
In class I only ask for volunteers to read aloud and try not to read myself. My reading has improved, but I'm still not confident in my reading ability. In class I find it very easy to read and write on the opposite side of the student. I've never thought about actually trying to read upside down, but I'll try it.
I'd give the upside down reading a chance. You never know...