This is what I came up with. It does seem like there's a correlation between early reading and glasses, but some of the studies (if I'm reading them correctly) seem to say it's influenced by genetics as well. HTH!

ETA: I am not horribly good at interpreting actual data, so I just scanned the conclusions of the paper.

http://cat.inist.fr/?aModele=afficheN&cpsidt=14386592

http://www.ncbi.nlm.nih.gov/pubmed/18579757

http://archopht.ama-assn.org/cgi/content/abstract/120/5/620

http://209.85.215.104/search?q=cache:23iCAHODbO0J:www.annals.edu.sg/pdf_1100/tang.pdf+%22near+work%22+OR+nearwork+myopia+children&hl=en&ct=clnk&cd=8&gl=us&client=firefox-a