The U-SPECS (universal spectacles) - developed at VU University Medical Centre in Amsterdam - can be used by anyone, but are primarily designed for use in developing countries where access to corrective eyewear is limited.

The glasses employ Alvarez lenses, which are easy to use: simply adjusting the dial on the spectacles changes the refraction for each eye from -6 diopter to +3 diopter. 

A 13 year old girl wearing a pair of U-specs provided by the Vision for a Nation programme in Rwanda.