Prescription lenses that can change focus from far to near and back again have been developed in Japan by TouchFocus.

When a sensor on the frame is activated the liquid crystals set into the lower half of the glasses change positions, altering the focus in that area and allowing the wearer to see objects closer to them.

Touching the sensor again returns the lens to your regular prescription.

Bifocal, trifocal or varifocal lenses already allow the wearer to use one pair of glasses to see at different distances but they are not suitable for everyone.

BBC Click’s Emily Bates reports.

See more at Click's website and @BBCClick.