Most pigeon breeders look and breed for certain traits. The eyesign theory to me was based on the genetic linkage between the genotype (such as racing genes) and phenotype (such as signs in the eye). To me, there is no such thing as a breeder's eyesign or dual purpose eye, there is only racing eye - high quality eyes that often seen in champions. If a bird does not carry the racing genes, there is nothing to pass on. Good racers will breed good racers. Poor racers sometimes breed good racers but I'm not going to practice that in my breeding program. Birds with beautiful eyes but can not race are for shows or bred for commercial reasons. Not all birds carry the same trait (eyesign) especially in different families will be good racers, but within the same family your odds will improve tremendously.
Thanks to Phil Lincoln for taking these great eyesign Photos, all photos taken under the same condition on June 1, 2003