Does anyone know of a simple eye simulator? (geometrical optics)

[Jet Black]

I'm looking for a "simple" calculator, most likely a matrix based thing, to allow me to work out the size of an image projected on the retina by an object of a given size some distance from the retina. being the eye, the thin film approximation is no good (i.e. if I have an object 3cm from the eye that is 5mm across, what is the extent of that object on the retina - yes I know it will be out of focus, but the maximum extent is fine)... anyone know of such thing anywhere?

 

[Andy Resnick]

There's a few models of the eye, one of the basic/standard ones is the "Gullstrand model"

http://www.visualopticslab.com/opti535/lectures/class02_08.pdf