The picture below is a picture of a racing pigeon with a full circle of black eyes. This kind of eye mark surrounds the crystal lens and is black (the darker the pigment, the better). The whole circle looks uneven and has a strong three-dimensional effect (the wider the circle, the wider it is. The wider, the better), this kind of pigeon is an excellent breeding pigeon. If the melanin of the eyes is light, the three-dimensionality is weak, and the width of the entire circle is very narrow, it will be relatively poor.
Whether it is a female pigeon or a male pigeon, all pigeons should choose full-circle eyes. This is a way of strengthening. You can find that the offspring produced are basically full-circle eyes. As long as the homing performance of the breeding pigeons is good, the homing rate of the offspring can basically be very high.