you asked a very cool and valid question...
first off : since you're learning to read notation , do you own "the real book"?
"the real book" is a book of jazz standards that is pretty much gospel in places like berklee... when i do get into serious studying i like to use "the real book" and to answer your question , YES , you're supposed to eventually memorize the notes because what would EVER EVEN stop your memory if you're repeating the same process everytime , ANSWER : nothing will prevent your mind from memorizing so if your eyes start to wander perhaps it means you have done all you can in that particular song :(in other words , you've learned it...) best bet is to get a "real book" and you'll have more than enough jazz standards to keep your sight reading sharp FOR A LIFETIME...
a wise wise sage once said "learn everything you can about music , AND THEN FORGET IT"... if you've conquered a piece of music , turn the page and start on a new piece !!!
Franky M.