A new range of contact lenses gives wearers telescopic vision like comic book hero Superman. Researchers from San Diego and Switzerland fitted a traditional contact lens with a magnifying ring which, when worn with a pair of Samsung 3D glasses, can magnify scenes by 2.8 times. The lens-glasses combination was designed to help restore the sight of people suffering from age-related macular degeneration, or blindness. The contact lenses are 8mm in diameter, 1mm thick in the middle of the lens and 1.17mm thick in a magnifying ring around the edge. Small aluminium mirrors are fitted into this magnifying ring.
These mirrors bounce the light from objects in front of the wearer approximately four times within this ring before sending the image to the retina.
By the time this image hits the retina it appears magnified by almost three times. When the lenses are being worn in ‘ordinary mode’ this magnified image is blocked by polarising filters fitted to a pair of modified Samsung 3D glasses. To switch to ‘telescopic mode’, the wearer can change these filters so that the only light that hits their retina is the light created by the magnified process. The lenses have tiny channels along the surface that let in oxygen and make the lenses ‘breathable’. This means they can be worn for long periods of time. The researchers behind the project were led by Eric Tremblay from the École polytechnique fédérale de Lausanne (EDFL) in Switzerland and Joseph Ford from UC San Diego. They chose to modify the 3D glasses because they are already fitted with light blocking technology. The glasses create the 3D effect by blocking light to the left or right lens at different times. Tremblay and Ford wanted to design a system that could help restore sight to people suffering from age-related blindness. According to the study in Optics Express, age-related macular degeneration (AMD) is the leading cause of blindness for people over 55 in the western world. It causes central vision loss in more than 2 million people in the U.S. alone. ‘People with AMD and other degenerative eye disease can use magnifying visual aids to help distinguish details using the functional retina outside of the damaged central fovea. ‘Bioptic telescopes are the most common commercially available visual aids for low-vision. ‘These telescopes are mounted through spectacle lenses at an offset such that the telescope can be brought into view by tilting the head. ‘Bioptic telescopes are useful for some tasks, including driving, but many visually impaired people reject them due to their cosmetic appearance and interference in social interaction. ‘Head-worn approaches also offer only a narrow field of view (FOV) and require that the user turn their head directly towards the viewed scene.’
