Mr X picked his glasses up today. At first he looked off into the distance and said everything looked fine. Then he looked at the reading card and said..."it is double." I could have crawled under the table! I composed myself knowing that I had personally checked the glasses in and they were correct.....so it had to be a brain thing. So...I said"keep these on until you see the Dr. this morning. Your brain is trying to interpret what it is seeing." He halfheartedly went to the back to see the Dr. He came out later saying it was already better. Whew! I was getting ready to run back to the Optiboard.
So those of you who said that the direction does make a difference were correct. It seems so obvious nOW. ;O

To Shabbir, your explanation totally impressed me. I had to read it about 10 times, but now I have an understanding of how the prisms bring the eyes together to "meet."
Pete and Homer said it the simplest. Prisms can be divided in many different ways, but if you are going to split them, you better have them going in the right direction.
Otherwise, you will increase the imbalance, and the eyes won't "meet."
I learned a lot from this. Thanks to all of you!! Isn't it wonderful that we have optician friends all over the world to consult and learn with! Thanks to Optiboard......thanks STEVE!!!!!!