For the first time ever, an international collaboration of scientists, have created a contact lens which can shift between magnified and normal vision . This advancement in contact lenses could offer those with retinal problems an unobtrusive solution. A prototype of the telescopic contact lens being tested on a life-sized model of the eye. One of the main problems these new contact lenses could solve is age-related macular degeneration (AMD). AMD is the loss of central vision caused by retinal damage that gets worse with age. Standard contact lenses aren’t useful since they only correct for the eye’s focus but cannot help with the fact that the retina is damaged. The current solution is to use bulky glasses that have mounted telescopes or surgical implants in the eye which help to magnify the light coming into the eye onto undamaged parts of the retina. Surgical implants are invasive and expensive, thus not ideal. Instead, Eric Tremblay from the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and his team including scientists from the U.S, have designed a contact lens that consists of a telescope. The new contact lens is made of a plastic called polymethyl methacrylate (PMMA). It works by using tightly fitting mirror surfaces to make a telescope that fits within a space that is a millimeter thick. This fits within the contact lens and allows the lens to have a magnified mode and a normal mode. The normal mode is at the center of the lens and the magnified area is ring-shaped and at the edges of the contact lens. The telescope can achieve x2.8 magnification. Tremblay says, ‘A user can switch between normal and magnified vision…and to do this switching, you would use a pair of off-the-shelf 3D TV glasses that we have modified slightly.' The glasses act as polarizers which can block either the magnified area or the normal area. A prototype was made and tested with computer modelling and by creating a life-sized model of the eye. It was found that the magnified image was of greater quality than other magnification techniques. But before this becomes commercial Tremblay says some refinements need to be made. One of which includes using a material that is gas-permeable. PMMA is gas-impermeable so if this was used the eye would not be able to get oxygen, therefore they cannot be used for long-term wear. Tremblay says, ‘We are now trying to build the lens using standard contact-lens materials that are gas-permeable…these will ensure that the cornea is receiving plenty of oxygen and so can be used safely all day long.’ The team hope to see clinical trials being carried by the end of the year, so watch this space. Source
