The vintage 1972 Blythe doll is 11-12" tall, has a large vinyl head with very distinctive luminous eyes and unique to this doll is that they change color too.  She has a string with a ring at the end, that when pulled (pull it straight out horizontal, not downward), her eyes changed to a different color; purple or amber and blue, pink, green.  Her tiny body is fully jointed and her hair is rooted, she came as a redhead, blonde or brunette. She wore a mod type dress with tall plastic boots. 

Clothing is marked:  BLYTHE™  by Kenner

Blythe doll mark 

 BLYTHE ™ KENNER PRODUCTS Cincinnati,

Ohio © 1972 G. M. F. G. I.

Patents Pending Made in Hong Kong. 

(G.M.F.G.I = General Mills Fun Group Inc.)

Blythe dolls were reproduced by Hasbro who bought Kenner from Tonka Toy and Takara of Japan also made Blythe dolls.