Scientists have created a slim telescopic lens that has the ability to switch its magnified vision on and off.
While contact lenses are successful in correcting a number of vision problems, older patients suffering from age-related macular degeneration (AMD) aren't so lucky. Simply re-focusing the eye is not enough to overcome the retina damage, according to an Optics Society press release.
ADM is the leading cause of blindness in the U.S. and most of the western world. The visual aid will help ADM patients by spreading light to the non-damaged parts of the retina. This could vastly improve their everyday lives, allowing them to read and easily recognize faces. Previous aids invented to serve the same purpose have not caught on because they have either been large and bulky, or needed to be implanted surgically.
"For a visual aid to be accepted it needs to be highly convenient and unobtrusive," said co-author Eric Tremblay of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. He believes a contact lens will be the most popular alternative.
The new lens uses "tightly fitting mirror surfaces" to create a tiny telescope that can be incorporated into a contact lens only a millimeter thick. The telescopic lens will allow the wearer to easily switch between regular and magnified vision.
The patient would wear a pair of liquid crystal glasses, originally used to view 3-D movies. The glasses would be able to either block or allow the magnifying qualities of the lens. The product was tested with computer modeling and fabricated lenses. The team build a life-size model of a human eyeball with the ability to capture images through the new lens system.
The tests showed clear images with a much larger range of vision, proving the project to be successful.
There were some slight glitches, the grooves in the lens used to correct color caused some vision obstructions and made the device unwearable. In the future, the team hopes to revise the lens to be made from gas-permeable material to correct color, so the grooves will not be necessary.
"In the future, it will hopefully be possible to go after the core of the problem with effective treatments or retinal prosthetics," Tremblay said. "The ideal is really for magnifiers to become unnecessary. Until we get there, however, contact lenses may provide a way to make AMD a little less debilitating."
