W. Fink et al., VISUAL MAPPING UNDER HIGH AMETROPIA - A C OMPUTER-AIDED SIMULATION USING RAY-TRACING, Klinische Monatsblatter fur Augenheilkunde, 208(6), 1996, pp. 472-476
Purpose A computer program developed by the authors allows to calculat
e the path of light rays coming from an object through all the refract
ive surfaces of a Gullstrand model eve until it reaches the retina, Me
thod The program calculates several hundred light rays for every point
of a given object. A menue allows to modify optical and morphological
parameters in an interactive way. For instance, the indices of refrac
tion, the radii of the cornea and of the cristalline lens, as well as
the length of the bulbus can be modified, Further, one can add seeing
aids such as eve glasses or a contact lens, or implant an artificial i
ntraocular lens, The seeing aids may be decentered and/or tilted. Resu
lts The code calculates also the visual impression by projecting the i
mage from the retina back to a screen at the distance of the object, w
here the human brain ''sees'' the object, For image interpretation we
use a normal Gullstrand eye with a very small aperture stop, Tn this w
ay we can simulate the visual mapping (visual impression) of a correct
ed or uncorrected ametropia. Conclusions In this paper we present two
nontrivial examples: we calculate the regional polyopia (''Bildverdopp
elung'') and the annular scotoma which appear whenever a high myopia o
r aphakia are corrected by eye glasses.