Hello Force you need to be concerned NOW! the eyelets is what supports the nipples. the reasons they are coming loose are many however as most our weight is carried by the back wheel and therefore it gets more abuse and it serviced ad trued more often it is not uncommon or them to start coming loose fisrt.
in fact front wheels vastly outlast rear wheels for the simple fact thay are not carring as much weight and that weight has a natural shock absorber (your elbows) they just last longer.
you may want to look closer you may have tiny cracks around the eyelets. are these tubolars?
__________________
“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk