Dahlia tubers must have an eye to sprout but unlike potato tubers dahlias do not have eyes all over the whole tuber. Dahlias only have eyes right where the tuber connects to the main plant stem. It is not uncommon for tubers to break away from the main plant stem and leave behind the eyes. When dividing dahlia clumps you must always carve away a bit of the stem to go with the tuber and even then it is possible to get a tuber with no eye. Your best bet now is to pot up all the tubers without visible eyes in a loose slightly damp soilless mix and put them somewhere warm. If their eyes don't swell and sprout then those tubers are useless for planting.

In the spring after winter storage, If I dont see a sprout already forming, I move the tubers into plastic bags (which I leave open) with moist peat moss. If I dont get a sprout, then I dont waste the space that a pot takes up. I can put 6-8 tubers in each bag.