Dear Sir/Madam

Some times it is easy to designed a system in reverse way. What we need at the image space, will model into object sapce and what are there in object space can model into image space.

I have desined a Ramsden eyepice in reverse order using two plano convex lens. Aperture type is entrance pupil diameter with 3mm Dia., and 3 fields points are there 0 degree,  5 degree, -5degree. 

Now i wish to flip the whole system, how can I do this? 

I am attaching the zemax file of eyepiece design.

Thanks