'Gecko vision': Key to the multifocal contact lens of the future?May 08, 2009Rockville, MD - Nocturnal geckos are among the very few living creatures able to see colors at night, and scientists' discovery of series of distinct concentric zones may lead to insight into better cameras and contact lenses. The key to the exceptional night vision of the nocturnal helmet gecko is a series of distinct concentric zones of different refractive powers, according to a study published in the Association for Research in Vision and Ophthalmology's peer-reviewed, online Journal of Vision ("The pupils and optical systems of gecko eyes," http://www.journalofvision.org/9/3/27). This multifocal optical system is comprised of large cones, which the researchers calculated to be more than 350 times more sensitive than human cone vision at the human color vision threshold. "We were interested in the geckos because they - and other lizards - differ from most other vertebrates in having only cones in their retina," said project leader Lina Roth, PhD, from the Department of Cell and Organism Biology at Lund University in Sweden. "With the knowledge from the gecko eyes we might be able to develop more effective cameras and maybe even useful multifocal contact lenses." The nocturnal geckos' multifocal optical system gives them an advantage because light of different ranges of wavelengths can focus simultaneously on the retina. Another possible advantage of their optical structure is that their eyes allow them to focus on objects at different distances. Therefore the multifocal eye would generate a sharp image for at least two different depths. Geckos that are active during the day do not possess the distinct concentric zones and are considered monofocal, Roth said. The scientists also developed a new method to gather optical data from live animals without harm with their modifications to the Hartmann-Shack wavefront sensor. "Studies of animals with relatively large eyes, such as owls and cats, have included surgery and fixation of the head," the article states. "In this study, we demonstrate that it is possible to obtain high-resolution wavefront measurements of small, unharmed gecko eyes without completely controlling the gaze or the accommodation of the animal eyes." Association for Research in Vision and Ophthalmology |
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| Related Contact Lenses Current Events and Contact Lenses News Articles Cataract surgery helps AMD patients; steroid improves DME; online eye health forum This month's Ophthalmology, the journal of the American Academy of Ophthalmology (Academy) reports on a national study that finds cataract surgery is likely to benefit patients with age-related macular degeneration (AMD) at all stages of the disease, on a clinical trial showing that the steroid triamcinolone may be effective in advanced diabetic macular edema (DME) patients when standard treatment fails, and on the public's use of two Academy-sponsored online eye health forums. A drug-dispensing contact lens Taking eye drops multiple times a day can be difficult for patients to do, and because of blinking and tearing, as little as 1 to 7 percent of the dose is actually absorbed by the eye. Sight for sore eyes In a world-first breakthrough, University of New South Wales (UNSW) medical researchers have used stem cells cultured on a simple contact lens to restore sight to sufferers of blinding corneal disease. UAB Tear Research Focused on Contact Lens Risks, Benefit Contact lenses are great for sight, but do they have an impact on general eye health? Researchers at the University of Alabama at Birmingham (UAB) School of Optometry are working to answer that question by analyzing tears. Violent Video Games Can Improve Vision Video killed the radio star, the old song goes - but violent video games, a new Tel Aviv University study finds, can also improve the real-world vision of teens who play them. Eye exercises help patients work out vision problems, UH optometrist says You've probably been there. In a doctor's office, being advised to do what you dread - exercise. You get that feeling in your gut, acknowledging that, indeed, you should exercise but probably won't. Now imagine that the doctor is your optometrist. Knobbly kneed ID Forget LED thumb-pad identification devices, complex retinal laser scanning, or even computerized iris recognition, the way forward for biometric validation is a quick X-ray snapshot of a person's knees, according to a report published in the International Journal of Biometrics. Strategy Discovered for Fighting Persistent Bacterial Infections Researchers at National Jewish Health have discovered a promising strategy for destroying the molecular scaffolding that can make Pseudomonas bacterial infections extremely difficult to treat in cystic fibrosis patients, wearers of contact lenses, and burn victims. Jerry Nick, MD, Associate Professor of Medicine at National Jewish Health, and his colleagues report in the April 2009 issue of The Journal of Medical Microbiology that a long string of aspartic acid molecules disrupts the molecular bonds that hold together the structure supporting Pseudomonas biofilms. Biofilms: Even Stickier Than Suspected Biofilms are everywhere - in dental plaque and ear canals, on contact lenses and in water pipelines - and the bacteria that make them get more resilient with age, finds a new study in FEMS Microbiology Letters. Contact lenses are home to pathogenic amoebae Contact lenses increase the risk of infection with pathogenic protozoa that can cause blindness. More Contact Lenses Current Events and Contact Lenses News Articles |
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