have you put the hd mod in your overrides folder, instead of just packages? you can also download delphy’s sims 3 dashboard and scan your mods folder to check if you have any conflicting mods. dont forget to clear your caches! (delete every file with “cache” in the name in your The Sims 3 folder, but not any folders)
Yes, tried all that but it did not work
Did you take the horses into CAS after you installed the eyes? And did you recolor the eyes so they have the shine?
Yep, did that. Some horses I've purchased even had the second colour a light blue or white because apparently it was working with their previous owners I also looked in game after going into CAS if maybe it wasn't showing in CAS but in game (maybe because of a bug), but the eyes still looked the same after CAS and recolouring them