The U-SPECS (universal spectacles) can be used by everyone, but is primarily meant for children in developing countries. It is easy to use: simply adjusting the knob on the spectacles changes the refraction for each eye from -6 diopter to +3 diopter. Because the focus of the glasses can be adjusted, no optician is needed and the cost for the adjustable glasses is less than 4 euros. The concept of these adjustable spectacles was developed at the VU University Medical Centre in Amsterdam, The Netherlands.
U-specs lenses are formed from two saddle-shaped parts mounted together. These parts can slide in opposite directions changing the lens power from -6D to -1D. This makes U-specs truly universal.
The U-specs concept was developed by a team of VU Medical Centre in Amsterdam led by Dr. Rob van der Heijde. The shifting lenses were invented by Nobel Prize-winning physicist Luis Alvarez. Dr. Van der Heijde converted his theoretical concept into universal spectacles.
Click this link to learn more about the U-SPECS (universal spectacles): http://www.u-specs.org.