Cutting and Beveling Lenses:
Based on our research of similar projects addressing URE in the developing world, we’ve established that groups are confronting the issue in two different ways: through traditionally manufacturing eyeglasses and through reinventing eye glasses (i.e. to make the prescription self adjustable). We have decided to utilize traditional eyeglasses instead of developing new technologies to address URE. Traditional eyeglasses have three main advantages over currently developed technologies. First, traditional eyeglasses can correct for astigmatism, a condition common in equatorial regions where UV exposure is more prevalent. Second, the availability of stock or donated materials may enable the project to incur low capital costs at the outset. Third, global media have created preferences in residents of developing countries for styles popular in developed countries, including those for eye wear.
Furthermore, donated eyeglasses taken from the United States to developing countries often remain unused because it is challenging to match prescription, size, shape, and style to a specific recipient. This is especially relevant for astigmatism correction, which depends on the orientation of the lens within the frame being correct for the individual patient.
There have been several suggested designs for the lens cutting device, which takes a lens blank and shapes it down to the correct size to fit a frame. The first machine that we developed could grind down new or donated plastic lenses to an appropriate shape and size. In August 2011, two Bucknell students and a Guatemalan partner (Pedro Navichoc) manufactured the grinding machine at his machine shop in San Pedro, Guatemala using locally available materials and fabrication processes and with material costs of less than US$20. The prototype grinding machine is fabricated from steel and utilizes a door hinge and an electric motor. The primary issues with this machine were that it could only produce circular lenses and it was time intensive to grind the lenses down to size. Therefore, the engineering team went back to the drawing board…
The latest lens cutting machine (shown in the photos at the top of the page) was created by Paden Troxell after consumer behavior research alluded to the team the need to create lens shapes of various sizes, other than circles. The current model uses a router to cut a lens blank in a way that mimics the shape of a lens template. With this machine, we are able to cut lenses to fit any frame size or shape, enabling us to meet consumer needs and desires. The machine is primarily composed of wood to hold the router in place. Routers are readily available in Guatemala, as is wood, therefore the machine will be able to be made using local materials and labor.