McDonald was also the third physician in the world to perform a procedure called conductive keratoplasty -- a noninvasive surgery for farsightedness that involves using radio-frequency energy to heat small spots around the cornea.

CNN: Her vision: Better, clearer sight

Then, the waves' frequency is tweaked and the sample blasted head-on in order to heat it.

ECONOMIST: Acoustic microfluidics

Record high temperatures are occurring with far greater frequency than in decades past, and crop yields decline sharply in extreme heat.

CNN: Extreme heat and droughts -- a recipe for world food woes