Why can't you ask a prescription lens specialist at a specialty store? Are you trying to fill a prescription?

according to -- Barry Santini, Master Optician and President of Long Island Opticians:

http://www.optcorp.com/product.aspx?pid=38 3-404-6872

I will add the comment that Mr. Santini's "hairspray can" should be visualized as standing upright, as if it were on a bathroom counter top. Thus the vertical axis has flat curvature (i.e., radius at infinity), or "least power," while the horizontal axis has high power, because of the curvature of the can...i.e, short radius. As Mr. Santini describes, the axis of astigmatism would thus be 90 degrees. Zero degrees is horizontal to the left... a departure from conventional graphing convention, as learned in high school algebra trig class, where zero degrees is horizontal to the right.

Unfortunately, Mr. Santini does not tell us whether positive 10 degrees is clockwise, or counterclockwise, from horizontal left. Can anyone complete this matter?

I Googled far and wide for information on astigmatic measurements within eyeglass prescriptions. Amazingly, I could never get an answer to whether axis was measured CW or CCW, from the 9 o'clock position. Wikipedia finally came to the rescue. It's CCW:


The Axis is the horizontal, vertical or diagonal angle of the cylindrical correction. The axis is measured in a clock face that starts with zero degrees in the 9 o'clock (or west) direction, and increases through 90 and 180 degrees in a counter-clockwise direction.


Your prescription deviates in form from all the examples I have seen on the internet. Look at Wikipedia's example, and post again. What might "BC" mean?

I am not an optician or medical professional.