Helmets are supposed to be replaced every five years, if there is no damage to them in the meantime. I bought my last helmet before I bought Winston, so it was well over five years old.
But, if you come off your horse and your helmet gets banged, you are supposed to replace it immediately -- even if you can't see any damage. The internal structure may be compromised, rendering the helmet less effective. I came off of Winston a few times, and there is a big gash on the side of the helmet from one of those unplanned dismounts. I sold Winston a few years ago.... but I kept riding in the same helmet. I know that I'm way overdue for a new helmet.
Not that I haven't been looking. Sort of. The thing is, most helmets are not comfortable on my head. This is true of bicycle helmets and motorcycle helmets too. My head does not like helmets. And, then, there is the whole style thing. The helmets that were comfortable were ugly. The cute ones weren't comfortable. And, the gorgeous ones were way out of my price range so I didn't even try them.
But I watch others at clinics and on YouTube videos and just drool. I have particularly suffered from helmet envy with my trainer. Sandy has a beautiful helmet.
After years of internal debate, I gave in and bought myself a drool-worthy helmet for my birthday. It came last night. I wore it all over the house. Brett threatened to take a picture of me cooking dinner while wearing my new helmet. Its super comfortable and is, I think, worthy of wearing when riding a princess mare. I thought about getting the one with crystals, but I'm not a bling sort of girl. I choose the classic model.