actually both are correct...see following entry from Websters Online Dictionary
Merriam-Webster Dictionary Online
One entry found for dyslexia.
Main Entry: dys·lex·ia
Pronunciation: dis-'lek-sE-&
Function: noun
Etymology: New Latin, from dys- + Greek lexis word, speech, from legein to say -- more at LEGEND
: a variable often familial learning disability involving difficulties in acquiring and processing language that is typically manifested by a lack of proficiency in reading, spelling, and writing
- dys·lex·ic /-sik/ adjective or noun
and
Main Entry: 1an·orex·ic
Pronunciation: "a-n&-'rek-sik
Function: adjective
1 : ANORECTIC
2 : affected with or as if with anorexia nervosa
you'll find most teachers and librarians still use dyslexic and anorexic (I did a poll today)
It is ridiculous to set a detective story in New York City. New York City is itself a detective story...
AGATHA CHRISTIE, Life magazine, May 14, 1956