New research shows that a portable, battery-operated fluorescence microscope, which costs $240, stacks up nicely against devices that retail for as much as $40,000 in diagnosing signs of tuberculosis.

The earliest example of a stereo microscope was designed and built-in 1671 by Cherubin d’Orleans, though it was a pseudostereoscopic design, which had major flaws. Only by application of additional ...