PURPOSE. During growth, the retina analyzes the projected image to achieve a close match between eye length and focal length. Because the messengers released by retina and choroid are largely unknown, genes that are differently expressed in response to changes in the retinal image were identified. In addition, because glucagon may be important in the visual control of eye growth, the transcript levels of proglucagon were studied. METHODS. Reverse transcription-polymerase chain reaction differential display was used to identify genes that were differentially expressed in chick eyes that were deprived of sharp vision or treated with positive or negative lenses. Differences were analyzed through sequencing and database searches and confirmed by Northern blot analyses
