Many ophthalmic instruments direct light into the eye and it is useful to be able to model the efficiency of the lighting delivery system, the uniformity of light distribution on the retina and so on. In some cases light is focussed onto the retina, such as in laser treatment of diabetic retinopathy, and in other cases light is focussed onto the pupil so that it illuminates a wide field, such as in indirect ophthalmoscopy. The same NSC model can be used for both these situations, with different source geometry.

The optical media of real eyes are often not completely transparent, and non-sequential modelling in ZEMAX also provides powerful tools to investigate the effects on vision of a wide range of pathological and physiological changes in real eyes. By adding absorption, scattering and inclusions it is possible to model the effects on vision of such things as corneal scarring, cataracts, vitreous floaters and foreign bodies. It is also possible to look at light scattering from the edges of corneal or intraocular lenses.

The non-sequential eye model included here is Eye_NSC.zmx. It uses the same glass catalog as the sequential models.

Note that the number of pixels in the retinal detector can have a significant effect on computing time. The maximum aperture of the detector should not be too much larger than the area of the retina of interest, and the pixel size may need to be increased.

The Eye_NSC model, above.