It would depend, "pin eye" is sometimes seen in CB ball pythons, it is simply the severe reduction of eye size, so you have one normal eye and the other eye is extremely small. Many of these snakes go on to breed and live the average lifespan of the species. Something like this I would definitely breed; however, if it was an abnormality that severely inhibited the specimens's function (i.e. a fused vertebrae that prevents the animal from coiling and maintaining general posture), I would not even try.