Light ring like structures in chicken egg yolk? All our chickens eggs (4) please advice

[kb323818]

. We are year new to having chickens, and have 4 hens. Today morning I noticed all the yolks had round circles inside is that normal. I Made 6 eggs for the kids and all had it, 3 eggs from fridge and 3 fresh. I never noticed those rings before please advice

 

[Yorkshire Coop]

Hi

Glad you could join us here!!
Could you post a pic of an egg that is uncooked?