Evaluating Eye Sign - There is hardly any other topic that polarizes the racing pigeon sport more than the topic of eye sign.  There are fanciers who believe that the structure of a pigeon's eye has some meaning and value as to whether or not a pigeon will be a great racer or breeder.  Conversely, there are fanciers who believe that eye sign theories are totally invalid and foolish.  Because there is little definitive scientific evidence on this subject, as with many theories, the validity and reliability of eye sign theory is strictly a matter of personal faith and preference. 

This video introduces the general concept of eye sign theory.  It recommends studying eye sign on a clear day with bright sunshine using an eye loupe (preferably higher than a 10X).  The video targets four areas of the eye for evaluation: (1) the iris, (2) the "circle of correlation" between the iris and the pupil, (3) the pupil, and (4) the "inner muscle" inside the outer rim of the pupil.  While the Lamberton's do not actively use eye sign theory in their management program, it is only because they have found other reliable methods to evaluate the racing and/or breeding abilities of their pigeons.  Even so, the validity and reliability of eye sign theory remains an interesting question that they they continue to study.