Simple as the solution of adjustable glasses may seem, it involved making use of an invention by a Nobel prize winning physicist (Dr. Luis Alvarez), the invention of an adjustment mechanism (the patented worm wheel) and production technology from a Philips supplier which revolutionized the CD/DVD production.
The production of the lenses of the glasses requires great precision in finding the right way to injection mold the plastic. The lenses of the Focusspec® are made of high-quality polycarbonate. The frame and temples are made of high-grade industrial plastics. The frame, lenses and the worm wheel are put together by ultrasonic welding, making the spectacles less vulnerable to dust and dirt (we have had no complaints so far during our field tests). Silicone parts are used in the newest model of the Focusspec® to make the glasses fit around different noses. “We had no complaints during our fieldtest about dust and dirt.”
The lens consists of two optical lenses with third grade surfaces. Because one lens is the exact inversion of the other, the moment they are placed exactly behind each other the strength of the lens is zero. Converting the lens along the x-axis changes the intensity of the Alvarez lens. Doing the same thing for the y-axis changes the astigmatic correction of the Alvarez lens. The Alvarez lens rectifies all refraction and astigmatic deviations by displacing one lens over the x- and y-axis and by turning the complete lens around the z-axis (optical axis).
Various specialists in the field of mathematics, applied physics, moldmakers, materials and injection mould experts are working closely together to get the right quality glasses. At the same time, there is a trade off with our goal to keep production costs at a minimum so as to make Focusspec® affordable to the people who most need them, people that live in rural villages in Africa, Asia and other parts in the world.
The Focusspec is currently available in the colour Classic Black. Should you wish to order different colours, please contact Focus on Vision.