It's one of the most delicate operations imaginable: An eye surgeon excises a piece of membranous tissue next to a patient's retina that threatens to damage or obscure the light-sensitive cells. Such "vitreoretinal surgery" can save the vision of someone whose eyes have been damaged by diabetes or trauma, but conventional microblades and microscissors can tear fragile tissues, and attempts to use lasers haven't succeeded. Researchers at Stanford believe they've developed a better option-a needle-sized "plasma knife" that cuts via blasts of electricity.

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