Difference in prescriptions follow up

[nickppatel]

I posted awhile back stating that my contact lens prescription is about -8.5/-9 and my spectacles prescription is about -12/-12.5 (cycloplegic, that is; regular fitting gives about -11/-11.5 or so).  Dr. Hagan stated that something must be wrong because nothing would account for that big a difference in prescriptions.  I have been thinking about how this could be, and now realize that an important factor may be the fact that I have very deep set eyes.  The distance between my eyebrows and pupils is probably at least 1.5 cm if not more.  This seems like it would substantially increase the vertex distance when prescribing spectacles and thus the power of the spectacles.  

Does this seem like a possible explanation for the difference in power?  It's all I can think of since I see almost perfectly out of both contacts and specs.

Thanks in advance, doctor!

[nickppatel]

I'm ok with any doctor answering ... just want to know if that kind of vertex distance can theoretically account for that large a difference in spec/contact prescription.

Thanks

[Ray T Oyakawa, MD]

Post to Dr. Hagen on odd days.

Dr. O.