Contact lens gives telescopic sight
Contact lenses which give the wearer telescopic vision could help people suffering from age-related blindness, according a research study.
The technology, developed by the Swiss Federal Institute of Technology (EPFL) in Lausanne and the University of California, San Diego, can switch from normal vision, using a pair of modified 3D television glasses, to magnify objects up to 2.8 times.
Eric Tremblay, lead researcher with EPFL, said the contact lens, which is 1.17mm thick, uses a ring of optics to magnify the view and liquid crystal shutters to block different optical paths, allowing the user to switch between normal and magnified vision.
In a report written for the Optics Express Journal he said the development of eye-integrated magnification devices started in the 1960s but many were too thick for sustained use.
He said: "Hybrid spectacle/contact lens approaches have also been investigated, but have not gained acceptance due to poor cosmetics, a limited field of view and vestibular conflict due to the image stabilising nature of eye movement in the optical system."
He added that a fully implantable intra-ocular miniature telescope had become available in magnifications of 2.2 times and 2.7 times, which offered improved appearance and compatibility with social interaction, scanning with eye movement, and a relatively large retinal field of view, but the downsides were limited light collection and that those who received it would need surgery.
The current lens, which has been tested on a model of a human eye, is designed in a gas-impermeable polymer commonly used for early contact lenses, according to the report.
Modern contact lenses need high levels of gas permeability so future versions would have to be made from rigid gas permeable polymers, Mr Tremblay said.
The work has been funded by the Defence Advanced Research Projects Agency, an agency of the United States Department of Defence responsible for the development of new technologies for use by the military.