Eyelink1000: Converting Arbitrary Units into Diameter

Hi,

I'm using the Tower Mount Eyelink 1000 and am trying to convert arbitrary units from the eyelink into diameter. From past messages, i know that 'NewestFloatData' only returns the arbitrary units in the .pa field.

Now that all i have is a bunch of raw units how can I convert these into diameter?

Are they somewhere in the edf file that I can access? What would that be under?

The other concern that I had was that i recalibrated for every subject, which means that the arbitrary unit scale is not same for every participant? Any suggestions on how to deal with this if I need to convert the arbitrary units?

Thanks,
-Russell Cohen Hoffing