My Eye's On You

Picture-perfect vision, with lovely dark pupils and irises of any color you want. Who wouldn't want that? Every person who wears glasses or contact lenses, or who just has that classic wish of the pilot or bird watcher - to see just a little bit better, farther, or more clearly at night - or who, vanity of vanities, wants slightly brighter green eyes, would be delighted to hear that stem cell research is moving us closer to the day when eyes might be created in the lab and implantable. Looming is the prospect of creating human eyes (or at the very least, central components of the eye) for the purposes of replacing, repairing, or regenerating unhealthy or damaged tissue. Scientists are finding pieces of the puzzle, those factors that control the generation of eyes (Nature, 449:1058-62, 2007). As eye researcher Nicholas Dale of the University of Warwick told LiveScience, "If you knew all the genes, and how to turn them on, that you needed to make an eye, you could start with very early embryonic cells and turn on all the right genes and grow an eye in a dish." If you think growing an organ in a dish sounds like science fiction, think again - in "Betting on Better Organs," you can read about a US biotech that's growing human bladders in a laboratory from a small snippet of cells. The eye is considerably more complex than the elastic bag that functions as a bladder, but there's a long history in eye regenerative medicine, by stem cell research standards. Ten years ago, a group used autologous cells from two patients each with one eye damaged by alkali burns, and both showed "striking improvement" after two years of follow-up (Lancet, 349:990-3, 1997). In 2004, Advanced Cell Technology reported it had generated the first retinal cells from human embryonic stem cells. More recently, researchers at the Medical College of Wisconsin have begun to work on the repair of the eye with stem cells - including partially restoring the vision (enough to be able to drive an automobile) in a maintenance engineer who was burned by sodium hydroxide. But before you throw away your glasses, note that the studies that isolate the signal that turns on the generation of entirely new eyes have been performed successfully only in tadpoles. Naturally, the work on stem cell therapies in the eye is mostly clinical and offers hope for those with severe eye damage, blindness, macular degeneration, cataracts, and more. But why stop there? Scientists such as Jay and Maureen Neitz at the Medical College of Wisconsin have been experimenting to see the effects of giving humans the ability to see different amounts of color when looking around the world, from dichromatic to tetrachromatic vision to even infrared. Imagine eyes that are even better in terms of mechanics or aesthetics than the best endowed pilot, sharpshooter, or actor. How far from therapy for cataracts is the use of a gene for night vision? Scientifically, perhaps not far, but what about ethically? The answer hangs on how you view enhancement. Literally. There are those who oppose the improvement of human nature on the grounds that we ought not to play God, or engage in risky research with no clinical benefit. But we are a society that enhances vision all the time with optical devices, ranging from night-vision goggles to colored contact lenses. I find it difficult to believe that building these changes into the eye itself would be morally more problematic. If such technologies are available, and the implantation and maintenance of "eyes from the dish" is safe and effective, I would argue we should not draw an arbitrary line between enhancement for eyes versus enhancement for any other aesthetic feature on the body (such as noses or breasts). Each of us may well have to decide just how far we are willing to go in terms of enhancing our perception. But the vision of better vision is coming to fruition. I'd keep an eye on it. Glenn McGee is the director of the Alden March Bioethics Institute at Albany Medical College, where he holds the John A. Balint Endowed Chair in Medical Ethics.gmcgee@the-scientist.com

My Eye's On You

What to think about night vision, tetrachromatic vision, and other visual enhancements?

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