I searched the US National Institute of Health History Database and the earliest paper I could find other than on heat stroke was published in 1817 in London in the Journal of Science and Arts by E. Home titled, "On the effects of a paralytic stroke upon the powers of adjustment of the eyes to near distances."
Don't take that as the final word on the subject. That's a broad area and it's likely that many scientists through history have contributed but the documentation may not be available.
Answered Mar 24, 2011
Edited Mar 24, 2011