Charles Sheffield 
Sight of Proteus [EPUB ebook] 

In the 22nd century a combination of computer-augmented bio-feedback and chemo-therapy techniques has given man the ability not only to heal himself, but to change himself — to alter his very shape at will. But Form Change has its darker aspects, ranging from unautorized experimentation on human subjects to a threat to the very essence of humanity — a SIGHT OF PROTEUS.