It has long been known that human eyes have a powerful ability to focus because of three kinds of crystalline proteins in their lenses, maintaining transparency via a delicate balance of both repelling and attracting light.
Two types of crystalline are structural, but the third - dubbed a "chaperone" - keeps the others from clumping into cataracts if they're modified by genetic mutation, ultraviolet light or chemical damage.
The UC Irvine team painstakingly explored and identified the structures of the normal proteins and a genetic mutation known to cause cataracts in young children.
They found that the chaperone proteins bind far more strongly to the mutated proteins in an effort to keep the lens clear. One major problem: Every human eye contains a finite number of the helpful proteins. Once they're used up, the researchers learned, weakened ones quickly begin to aggregate and form blinding cataracts.
The study is published in the journal Structure.