Hello everyone,

I’m currently working on creating patient-specific eye models in Zemax based on the Liou-Brennan eye as a starting point. I’m converting standard Zernike coefficients (Z4, Z5, Z6) into sphere, cylinder, and axis values using equations below with R as the pupil radius. Then, I will want to compare with objective refraction data obtained from a Shack-Hartmann wavefront sensor in my clinic (please let me know if there is a better method for doing this).

At the moment, I have the retina set as the image plane. However, I suspect I need to compare the prescription at the corneal or even spectacle plane instead—specifically, at a vertex distance of 12.5 mm from the cornea.

My question is: Have I possibly set up my eye model backwards? Or is there a standard method for accurately translating Zernike coefficients to a prescription at the corneal (rather than retinal) plane? Forgive my poor optics knowledge…

Thank you in advance.