It sounds like something from science fiction: glow-in-the-dark butterfly eyes.
But believe it or not, Antónia Monteiro of SUNY, Buffalo, was able to make a butterfly that has luminous green eyes. Monteiro and her team inserted a new gene into the butterfly's genetic sequence--one taken from a jellyfish.
This gene codes for a green florescent protein that, in nature, makes certain jellyfish luminesce. By taking just that one bit out of a jellyfish sample, essentially attaching it to some modified DNA that naturally knows how to insert itself into a gene sequence, and then injecting the self-inserting DNA with the piggybacking jellyfish gene into some butterfly eggs, the researchers were able to produce a butterfly with glowing eyes. That's already been done with other insects, but this is the first genetically modified butterfly in history.
The idea isn't to produce weird looking butterflies; the glowing protein acts as a marker. That is, when you have succeeded in inserting it into a new organism, it's very obvious that it's there. This is just the basic research that may one day allow us to modify gene sequences on a larger scale--to get rid of genetically based diseases, for example.