Wise to the World

Is Gecko Vision the Key to Higher-tech Multifocal Contact Lenses?

By Judith Riddle
Senior Editor

A GROUP OF SWEDISH SCIENTISTS seem to think so. Nocturnal helmet geckos are among the very few living creatures able to see colors at night due to their unique ocular system, which researchers believe could be duplicated to develop better contact lenses and cameras in the future.

The key to the exceptional night vision of these nocturnal creatures is a series of distinct concentric zones of different refractive powers, according to a study published in the peer-reviewed online publication Journal of Vision, (journalofvision.org/9/3/27), from the Association for Research in Vision and Ophthalmology.

“With the knowledge from the gecko eyes, we might be able to develop more effective multifocal contact lenses and maybe cameras,” says project leader Lina Roth, PhD, from the department of cell and organism biology at Lund University in Sweden.

The multifocal optical system of the nocturnal gecko is comprised of large cones, which are 350 times more sensitive than human cone vision at the human color threshold, researchers say. This gives them the advantage because different wavelength ranges of light can focus simultaneously on the retina. Their eyes allow them to focus on objects at different distances, resulting in a sharp image for at least two different depths.

Study: Combined Dietary Factors Lower AMD Risk

A DIET THAT INCLUDES key nutrients and low-glycemic index foods is likely to reduce risks for AMD, according to the first study to analyze these factors in combination. The study was published in the May 2009 issue of Ophthalmology.

The study team included the Age-related Eye Disease Study (AREDS) researchers and was funded in part by the United States Department of Agriculture and the National Institutes of Health. Researchers analyzed data for 4,003 AREDS participants, involving 7,934 eyes. Earlier studies have demonstrated the AMD-protective effects of several nutrients and low-glycemic index foods, but this study is the first to associate specific food intake patterns with substantial reductions in AMD risk.

Subjects whose diets included higher levels of vitamins C and E, zinc, lutein, zeaxan-thin and omega-3 fatty acids, as well as low-glycemic index foods (fruits, vegetables, beans, whole grains) were at lowest risk for developing early and advanced AMD. Until clinical trials or prospective studies confirm these results, researchers say you shouldn't make specific dietary recommendations to patients.

Online Video Tips for Glaucoma Patients

TO HELP EDUCATE your glaucoma patients about their disease and the importance of regular eye exams and medication use, direct them to a new online series of short educational videos, called All Eyes On Glaucoma. The Web site (snipurl.com/glaucomavideos) features five short video messages from leading global glaucoma experts that serve as reminders for patients to play an integral role in the success of their glaucoma treatment and management.

Let's Talk UV Protection

NOW THAT SUMMER'S here, it's a good time to begin educating patients about how to protect their eyes from the sun's ultraviolet (UV) rays.

Following routine eye exams, mention that prolonged exposure to UV rays can cause sunburns to the eyes, or photokeratitis. This painful condition can result in temporary loss of vision for 1 to 2 days. The presence of pterygium, a growth of tissue that forms on the white of the eye, also can develop and require surgical treatment. And because UV damage is cumulative, it can lead to cataracts and AMD later in life. Solutions: Suggest patients wear sunglasses that block 100% of UVA and UVB rays and a wide-brim hat; wrap-around sunglasses or UV-blocking contact lenses.