In these distinctive glasses, the corrective power of the polycarbonate lenses is continuously adjustable via small rotating wheels. Two wave-shaped plates in each lens glide across each other and allow adjustments from –6 to +3 dioptres, correcting more than 90 per cent of spherical errors. With a simple construction, these glasses are suitable as a spare pair and for patients with fluctuating vision, such as due to diabetes or after eye surgery.