function time = eyeToFish(x,y,...
    xeye,yeye,xfish,yfish,vair,vwater)
% Travel time on the bent line between the eye 
% and the fish.
time = sqrt((x - xeye).^2 + (y-yeye).^2)./vair + ...
   sqrt((x-xfish).^2 + (y-yfish).^2)./vwater;
