I had noticed that several of our Paso Fino horses have very interesting eyes. Distinctly amber or lighter.
Here is a picture of Zara (AuSome Zarzuela by Don Cristobal Mako out of La Tentacion Mako), taken by Yvonne in December 2010:
The next photo shows Guajira (AuSome Guajira by Don Cristobal Mako out of Guanatanamera de la Raza). She was with us to be started under saddle a few years ago, when Yvonne took this picture. Guajira is now in NZ.
We have couple of other mares with similar eyes. It has always struck me as unusual and interesting. By coincidence (I was flogging google for other information), I came across an article about "Tiger eye" on a NZ website. It describes how "A researcher in the US has received a grant to study the genetics of "tiger eye" in Paso Fino horses". Quite interesting.
It is mentioned that tiger eye has a recessive pattern of inheritance. I have too small a sample of horses to draw any useful conclusions in that respect, but my observations agree with this this. Zara's sire Cali had dark eyes, so did her dam. Her full sister also has normal eyes. Two halfs sister out of another mare, however, have the tiger eye, and you can also see it in their dam. Some eyes are not as obviously yellow, but rather more like a dark amber, but close up, it is still pretty distinct.
I will see if I can find more photos with interesting eyes.