There's more than one definition of a blind seedling, see here
https://www.google.com/search?q=Blin...&bih=815&dpr=1
I couldn't find a good picture but what I call a blind seedling can have 1 or 2 cotyledons come up first,then in the center there's a small knob of green.
The plant doesn't die but stays as is and if it's a rare variety, I start chanting incantations over it and rarely, a new sprout will come up from that knob on the side/base of it..
Carolyn