They are NOT purposely bred (at least these ones) Read the whole link including page 2, the owners have an eyeless turtle that breeds like other turtles. Some of the offspring are also eyeless. It is the result of a fairly common recessive gene, the difference is they are sold rather than culled.
As for the 2 headed one, again it is something not that uncommon among reptiles, what is uncommon is that they survive. Here are some other "sports".
To me they are no worse than bubble-eyed goldfish and albino oscars.
look at the prices they charge especially the tanks and tanks with turtles its ridiculous i saw them advertised before on kingsnake they got rediculed for there prices
Guess I jumped the gun and over reacted, simply thought that they were being mass breed or genetically engineered...either way interesting though i still feel bad for the guyz!