How is ray tracing done for (colored) halos seen by glaucoma patients?   
      
   Can it be compared to a rainbow sight? (As is known,a light ray after   
   refraction and TIR in each water droplet is rotated by ~ 360- 47 deg  approx   
   to produce a perceived halo in the clouds of the sky opposite the sun).   
      
   By means of geometric optics (ray- tracing) how to show where exactly   
   reflection and refraction are occurring in structurally defective parts of eye   
   (cornea/ lens/anterior chamber/trab. mesh) to perceive such halos that a   
   normal eye cannot see.   
      
   It appears only open angle type produces halos and tunnel vision, so I was   
   curious to see a ray-trace, but had no luck in browsing internet.   
      
   TIA   
   Narasimham   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)