2011년 12월 20일 화요일

How to Care for Soft Contact Lenses

Enter the contact lens care aisle of most supermarkets and drugstores, and you'll find a confusing array of products.
Though daunting, it's essential to understand lens care: Not caring for your contact lenses properly can lead to a variety of eye infections, including some that cause blindness.
Actually, contact lens care is easier than ever. One-bottle care systems and disposable contact lenses mean that proper lens care involves much less time, expense and trouble than it did years ago.
Before we get started, understand that you should not switch care regimens without asking your eye doctor first. Some products are not compatible with each other, or with certain contact lenses. Using incompatible products can ruin your contact lenses or harm your eyes.
To make sense of all the bottles and boxes, it helps to know what steps are required to care for soft contacts.
It's particularly important to follow guidelines for safe handling of soft contact lenses in light of recent outbreaks of serious fungal eye infections associated with a popular (now discontinued) brand of contact lens cleaning/disinfecting solution.

The Basics of Soft Contact Lens Care: Clean, Rinse and Disinfect

  1. Wash your hands so that you don't transfer dirt and germs to your eye. Try to avoid moisturizing soaps, as they are not good for contact lenses. Dry your hands with a lint-free towel.
  2. Remove one lens and clean it with the recommended solution. Cleaning removes eye-produced buildup, cosmetics and other debris that impairs lens comfort. The FDA recommends that you rub the lens in the palm of your hand with a few drops of solution, even if you are using a "no-rub" product.
  3. Rinse the lens again to remove the loosened debris, making sure to take as long as the package directs: Rinsing is an important step.
  4. Place the lens in your clean lens case or lens holder and fill with fresh solution; don't "top off" your old solution. Disinfecting kills microorganisms on the lens. Disinfection time varies from product to product; check the package for details.
  5. Repeat steps two through four for your other lens.

Beyond Clean, Rinse and Disinfect

Protein. Depending on what kind of contact lenses you wear and how much protein your eyes deposit on your contacts, your doctor may recommend you use a product for protein removal.
While cleaning them does remove some protein, it can still build up on your lenses and make them uncomfortable. That's why the longer you wear lenses before replacing them, the more likely you are to need a protein remover.
For example, if you wear disposables, you probably won't need one; but if you wear the kind of lenses that are replaced only once or twice a year, you definitely will. Products for removing protein include enzymatic cleaner and daily protein removal liquids.
Eye dryness and irritation. Use contact lens eye drops to lubricate your eyes and rewet your lenses.
Eye sensitivity and allergies. A small percentage of lens wearers develop an eye allergy to the chemicals present in contact lens solutions. If this is the case with you, you don't need an additional product: You just need to switch products to those marked "preservative-free."

The Products: Cleaning, Rinsing and Disinfecting Solutions

Saline solution is for rinsing and storing contact lenses, when you're using a heat or UV disinfection system. You also may need it for use with enzymatic cleaning tablets or cleaning/disinfecting devices. Never use saline products for cleaning and disinfection.
Daily cleaner is for cleaning your contact lenses. You place a few drops in the palm of your hand and carefully rub the lens for as long as directed, usually around 20 seconds, making sure to clean both sides. Use other products for rinsing and disinfection.

Multipurpose solution is for cleaning, rinsing, disinfecting and storing your contact lenses. Clean your lenses as you would with daily cleaner, then rinse (as long as directed) and disinfect, all with the same solution; or rinse the lenses twice, then place them in the clean lens case with solution to clean and disinfect. When you are ready to wear the lenses, rinse them again. With multipurpose solutions, no other lens care products are necessary.

Clear Care by CIBA Vision
Hydrogen peroxide systems may help wearers who are sensitive to the preservatives in multipurpose solutions.
Hydrogen peroxide solution is for cleaning, disinfecting, rinsing and storing your contact lenses. With this product, you place your lenses in the provided basket and rinse them, then place the basket in its cup and fill the cup with solution to clean and disinfect your lenses.
Some lens holders for hydrogen peroxide systems have a built-in neutralizer (to convert the hydrogen peroxide to water, so it doesn't sting your eyes), but with others you need to add a neutralizing tablet.
After the disinfection and neutralizing step is completed, you can remove the lenses from the case and put them on.
Never rinse your contacts with hydrogen peroxide solution and apply them directly to your eyes without completing the entire disinfecting and neutralizing step. Doing so can cause a painful chemical injury to the eye.

Cleaning/disinfecting devices will, as you would expect, both clean and disinfect your contact lenses. Depending on how the brand is designed, cleaning is accomplished with either ultrasonic waves or subsonic agitation, whereas disinfection occurs via multipurpose solution or ultraviolet light.
The instructions for the devices are all a little different. In general, you first rinse the lenses, using either saline or multipurpose solution as directed. One brand requires rubbing with the saline, but most are no-rub.
Then, put your contact lenses in the device and fill it with the same type of solution as for the rinse. Place the lid on the device and plug it in to clean and disinfect your lenses.

2011년 12월 4일 일요일

Contact lens safety

Side effect preservative of soft lens. There is that put soft lens and side effect follow.
Have method next seven which prevent this side effect.
1. It is good for protection of eyes that all soft lenses goes side by side with glasses without putting more than up to 8~12 times and puts.

2. Lens washes and sterilize do must.

3. Oxygen transmission rate is high than Sopeuteurenjeu that cause much oxygen transmission rate bleeding, Geonjogam, inflammation day and like to wear RGP lens or that putting on time is restricted dream lens dream lens dream lens that give less that is dry as tear circulation goes well.

4. I must get thorough pre-inspection whether availability, allergy temperament of whether chemical agents of availability toxicity ingredient of whether availability, tear of whether can execute existence and nonexistence examination of eye disease, A/S and post-inspection is sufficient works in where is can put availability etc.. soft lens of whether is.

5. Must execute fit prescription selecting company's products which can believe.

6. when uses soft lens, put hygienically knowing well caution but does not put long hours, and when there is singularity, should consult with eye specialist immediately.

7. visit and examine ophthalmology regularly.

Wireless Display on a Contact Lens

A team of researchers led by Babak Amir Parviz, an associate professor of electrical engineering at the University of Washington, just published a paper in the 22 November edition of the Journal of Micromechanics and Microengineering that described a breakthrough in the development of an electronic contact lens with a built-in display.

Parviz, who collaborated with University of Washington ophthalmologist Tueng Shen and optoelectronics researchers from Aalto University in Finland, has for several years been working on contact lenses that will somedayaugment the wearer’s vision with external data or use sensors to collect data about the state of the wearer’s health.

The researchers say that they successfully created a single-pixel wireless display comprising a blue gallium nitride LED mounted on a transparent sapphire chip, an integrated circuit that doubles as a power harvester and controller for the LED, and metal interconnects. They also showed that a series of passive lenses (called Fresnel lenses) less than 1 micrometer thick, when placed on the surface of the contact lens about 360 micrometers away from the LED, can focus the LED light onto the retina in a way that makes it appear as though the single-pixel image is floating in space about 1 meter away from the eye. Otherwise, the image would be right up against the cornea, where the human eye is incapable of bringing objects into focus.

Of the high-tech miniature display, the researchers said that although it has only one controllable pixel, “…we have provided the first proof-of-concept technology demonstrations for producing multipixel and in-focus images using a contact lens by producing multipixel micro-LED array chips on transparent substrates and micrometer-scale Fresnel lenses that can be integrated into a contact lens.” In other words, the team is making significant progress toward the goal—an array of 3600 10-µm-wide pixels spaced 10 µm apart—that Parviz mentioned in the September 2009 IEEE Spectrum article “Augmented Reality in a Contact Lens.” Now that the researchers have demonstrated the ability to remotely control red and blue LEDs, doing so with green ones is the next step in order to produce full-color displays integrated into contact lenses.

Among the technical hurdles that remain is developing an improved power supply. The 5-millimeter-radius loop antenna used to draw power wirelessly in the experiments documented in the paper only harvests enough energy when it is within about 2 centimeters of the radio transmitter. Another problem is that the so-called bionic lens is made from polyethylene terephthalate, a form plastic that is not porous enough to be worn against the eye all day. Its poor oxygen permeability could lead to corneal swelling. But the team says it is already back in the lab, attempting to overcome these challenges.