I think the prolapse and pinkeye thing was mostly polled Herefords 20 or 30 or 40 years ago. My neighbor and I both have polled Herefords, he has had them for many years, along with other Herefords in our area. No prolapses in recent memory and pinkeye no more a problem than with any other breed. Pinkeye seems to be more a function of fly control and stubble height than breed these days. 

All breeds have had their problems at one time or another. Breeders logically take care of them or they will be out of business. Note current Angus genetic problems such as FCS/carriers for example. No one talks about them and the others very much but they will be figured out and bred out over time. jmho.

Jim at Dawn