By Jennifer Abney Anchor
.
Published: Mon, July 14, 2008 - 3:42 am
Last Updated: Mon, July 14, 2008 - 7:18 am
Jennifer Abney
The American Optometric Association estimates 30 million Americans wear contact lenses. Two-thirds of them are women. The majority of contact lens wearers are 25 and older, with 50 percent of them between 25 and 44.
There are two main types of contact lenses: gas-permeable and soft. Gas permeable contacts (technically referred to as rigid gas permeables) are made of rigid, yet slightly flexible plastic that allows oxygen to pass through the lens to the eyes. Most people find them comfortable to wear, but they may take a short period of adjustment. Gas permeable lenses are more durable than soft lenses and can correct many different types of vision problems.
Soft contacts are thin, gel-like lenses that contain water to maintain a flexible shape. Since they are so soft, many people can wear them without any period of adjustment. Daily wear soft contacts are designed to be taken out each night, cleaned and stored. These are the most popular kind of contacts, used by 80 percent of contact lens wearers in the U.S. Extended wear contacts are worn continuously (including at night), usually for up to seven days. Disposable contacts are lenses that are used for a specified number of days and then discarded. They must be removed each night.
The High Tech Contact Lens
Contacts are mainly designed to correct vision. Now, researchers at the University of Washington are trying to find ways to incorporate complex technology into the lenses. A device under development, referred to as a “bionic lens” or “e-lens,” integrates a miniature electronic circuit and LED lights between layers of polyethylene terephthalate (PET). It’s powered through radiofrequency energy transmitted to an antennae incorporated into the lens.
Electrical Engineering Researcher, Babak Parviz, Ph.D., says there are several possible uses of the high tech lens. Biosensors embedded into the lens could monitor a patient’s health (like glucose levels or intraocular pressure). Computer images could be sent to the circuit, enabling the wearer to see virtual displays, like a map, warning signal or message. Parviz says the technology may also be picked by the video game industry, allowing a wearer to play games or surf the net without the need for a display monitor. He envisions the computer generated images as being semi-transparent. Thus, as they are projected onto the visual background, they wouldn’t interfere with sight.
The high tech lenses are still in development. The current prototype has been tested in a rabbit eye and has been shown to be well tolerated without any side effects. A fully functional lens (i.e., one with working circuitry) has not yet been produced.
BIBLIOGRAPHY
“Advantages and Disadvantages of Various Types of Contact Lenses,” St. Louis: American Optometric Association, downloaded from website (http://www.aoa.org), June 2, 2008.
Bertsh, A., et al., “The Sensing Contact Lens,” Medical Device Technology, June 2006, Vol. 6, No. 6, downloaded from website (http://www.devicelink.com/mdt), April 22, 2008.
“A Focus on Vision,” FDA Consumer Magazine, July-August 2006, Vol. 40, No. 4, pp. 10-17.
Frischholz, M., “Wireless Pressure Monitoring System,” Medical Device Technology, September 2006, Vol. 6, No. 9, downloaded from website (http://www.devicelink.com/mdt), April 22, 2008.
Leonardi, Matteo, et al., “First Steps Toward Noninvasive Intraocular Pressure Monitoring with a Sensing Contact Lens,” Investigative Ophthalmology and Visual Science, July 2006, Vol. 45, No. 9, pp. 3113-3117.
Research compiled and edited by Barbara J. Fister
© 2008 Medstar Television, Inc. All Rights Reserved
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I’m sure there will be issues that will have to be faced such as with cell phones but they will be solved as will be the cell phone problems, but think of all the advantages. I would dearly love it if I could get a set of contact lens to display my blood sugar level at any time I wanted. I could throw away my glasses and blood glucose monitoring kits and all. I would imagine for the most part people will still show up for exams and what ever. I wouldn’t consider missing a dilated retinal exam once or twice a year or a A1C blood test regardless of what my contacts showed. But expand what these could possibly be used for in other areas and it is as you said amazing.