The lens of the eye is the only transparent tissue in the human body. In the past few years, scientists have determined that this transparency--critical for focusing light--stems in large part from the unique ability of the lens to activate a self-destruct program in its cells that aborts just before completion, leaving empty but sustainable cells that transmit visible rays.
A better understanding of how lens cells become and remain transparent should suggest ways to prevent lens-clouding cataracts. More than half of all Americans older than 65 develop these sight-blocking occlusions. The only recourse is to surgically remove the person's lens and insert an artificial implant, and even then, complications requiring a second operation occur in a large proportion of patients. Given that cataracts affect primarily older people, for whom any kind of surgery is worrisome, a method to slow, stop or reverse cataracts would be a great aid indeed.
This article was originally published with the title Dying to See.