Category Archives: contact lens

How are Soft Contact Lenses Made?

Have you ever wondered how soft contact lenses are made?  We found this Discovery Channel video from the show How Do they do it? showing how custom soft contact lenses are made.  

National Public Radio’s Medical Detectives Explore Increased Nearsightedness in the US

Photo of Child gazing out windowIn December 2009 we covered the results of a recent study Myopia Increasing Rapidly in The US Population. Recently National Public Radio’s Medical Detectives interviewed, Dr Susan Vitale, principle author of the study “1994-2004 National Health and Nutrition Examination Survey” and Dr. Don Mutti, an expert in myopia.  It’s a good listen and only a little over 3 minutes.

With myopia increasing at such a rapid rate in our population will it be long before the use of orthokeratology to slow the progression of myopia in our children becomes the standard of care?

Photo courtesy of Flickr user Pink Sherbet Photography,  D Sharon Pruitt

Top Ten Reasons to Buy Your Contact Lenses from Your Eye Doctor

1. You are guaranteed to get the correct lenses in the correct parameters

2. You are guaranteed to get unexpired lenses

3. If your lenses are not performing properly you don’t have to worry about exchanging your old lenses

4. You can exchange unopened, unexpired, unmarked boxes in new condition at your yearly eye exam

5. If you have a defective lens, we will replace it free of charge

6. We have the latest manufacturer’s rebates available to save you money

7. Competitive pricing

8. FREE shipping

9. You will be getting the lenses from an authorized distributor of the brand you wear

10. You will have the satisfaction of supporting a local business that cares about you and your eyes

Image courtesy of Flickr user Malkav.

Study Says: Myopia Increasing Rapidly in The US Population

The rate of nearsightedness in the US  has increased by over 66% in the past 30 years says a study published in the December 2009 issue of Archives of Ophthalmology

Thick GlassesA 66% increase in myopia is a huge change over a 30 year period. The new study tried to simulate the testing methods of the original 1972 study on nearsightedness in the US population.  The 1971-1972 National Health and Nutrition Examination Survey found that 25% of the US population between the ages of 12 and 54 were nearsighted vs the 1994-2004 National Health and Nutrition Examination Survey’s finding of 41.6%.  Increased nearsightedness was noted regardless of age, sex, race or education.

The authors concluded that it would be beneficial to identify behavioral risk factors that cause increased myopia.  If risk factors for increasing myopia are identified we may be able to slow the progression.

The big question is “what caused this increased nearsightedness in the US population”?  As eye doctors we are often asked what causes nearsightedness and the usual answer is that that we believe nearsightedness is a combination of genetics and environmental influences.  In the last 30 years our society has become much more near centric.  People spend hours glued to their computer monitors at work and home. Kids spend more time at near now then ever before with computer games, hand held games etc.

Numerous recent studies have shown that orthokeratology contact lenses can greatly slow the progression of nearsightedness

Finding ways to slow or halt the progression of myopia has been a longstanding subject of study in eyecare.  The process of using special contact lenses to reshape the front part of a patient’s eye to prevent the progression of nearsightedness and to allow the patient to see without glasses is called orthokeratology.  There are a number of different names for orthokeratology, orthoK, corneal molding, corneal reshaping and corneal refractive therapy are some of the most common names.

Almost a year ago the study, Controlling Astigmatism & Nearsightedness in Developing Youth (CANDY) showed that orthokeratology contact lenses reduced the progression of nearsightedness in kids between 9 and 16.  The authors of the CANDY study found that the amount myopia in children that did not wear the overnight Corneal Refractive Therapy lenses increased at a rate of .37D per year while those children wearing  the lenses progressed at only .03 diopters per year.

Another study, Corneal Reshaping and Myopia Progression published in the British Journal of Ophthalmology, conducted at the Ohio State University College of Optometry found that the eyes of the children wearing overnight orthokeratology lenses increased in length at a markedly slower rate than the studies’ non ortho-K lens wearers.

Lastly, the study Stabilization of Myopia by Accelerated Reshaping Technique (SMART) is in the first  of its five years and this past summer released preliminary results showing that again, orthokeratology lenses appear to markedly slowing the progession of nearsightedness in children.

While the rate of nearsightedness in the US population has increased significantly in the last 30 years it is comforting to know that there are safe and effective methods of slowing the progression of myopia.  Download a PDF of the study Increased Prevalence of Myopia in the United States Between 1971-1972 and 1999-2004

Image courtesy of Flickr member Foxtongue.

Study Shows UV Absorbing Contact Lenses Really Work.

Johnson & Johnson conducted a study using rabbits and concluded that UV absorbing contact lenses significantly reduced the UV induced changes in the cornea, aqueous humor (fluid in the eye) and the lens.  The study authors concluded that UV absorbent contact lenses were capable of protecting the cornea and crystalline lens of rabbit eyes from UV induced changes.

So the question is how does this affect humans?  There are a number of contact lenses on the market today that block most of the UV rays.  While we can’t guarantee that the results of the study would apply to humans we can generally infer that wearing this type of contact lens is beneficial for patients that spend a lot of time outdoors and do not wear sunglasses.

UV absorbent lenses do not protect our conjunctiva. The conjunctiva is the clear membrane that covers the blood vessels over the white part of the eye.  This is an important reason as to why UV absorbent contact lenses are not a replacement for quality sunglasses.  Excessive exposure to UV light on the conjunctiva is a leading cause for pterygia and pinguecula.  A pterygium is the fleshy growth that grows over the colored part of the eye, usually located at 3:00 or 9:00.  A pinguecula is the yellow bump on the white part of the eye, which is also located at 3:00 or 9:00.

While not a replacement for good sunglasses, using UV absorbent contact lenses, especially in children, is a good practice.

How to Insert, Remove and Take Care of Soft Contact Lenses

Coopervision has produced this 10+ minute video on how to insert, remove and take care of soft contact lenses.    There is a brief commercial at the beginning outlining the different kinds of contact lenses offered by CooperVision.  This video outlines the right way to do it.  Throw away that contact lens solution everyday!

How are Custom Soft Contact Lenses Made

Here is an interesting video from the TV show How It’s Made on how custom soft contact lenses are made.  The vast majority of soft contact lenses  prescribed today are mass produced and molded, however if you have a lot of astigmatism or wear special custom ordered contact lenses then the odds are good it was manufactured in a similar manner.

Encouraging Early Results in Nearsightedness Prevention Study

The first year of the Stabilization of Myopia by Accelerated Reshaping Technique (SMART) Study has produced some encouraging results in a recent announcement.  According to Dr. Robert L. Davis, co principal investigator of the SMART trial,  “The net effect of this contact lens fitting philosophy is to change the cornea shape for the sole purpose of reducing the amount of myopia as measured by change in refraction” .  “The results of the SMART Study so far are very exciting,” said Dr. Davis. “The outcomes of this study may revolutionize how we manage young nearsighted patients from this point forward”.

The SMART Trial involves 300 patients between the ages of 8 and 14.  The goal of the study is to see if having patients where overnight orthokeratology or corneal molding lenses will stop or slow the progression of nearsightedness.  The SMART Trial is the largest of its kind.  Other studies have also shown that preventing nearsightedness with ortho-K contact lenses is possible, such the CANDY Study.  A study from Ohio State Unversity suggested that wearing Ortho-K lenses overnight actually prevented the eye from becoming longer.  The SMART Trial has just completed the first year of the five year study.  We will continue to keep an eye on this potientially ground breaking study.

FDA Promotes Proper Contact Lens Care

FDA Taking Steps to Improve Contact Lens Safety

The U.S. Food and Drug Administration is taking steps to improve contact lens safety by reminding consumers of the importance of following proper cleaning and storing procedures. Consumers who do not follow instructions for contact lens care and use increase their risk of serious eye infections that can lead to blindness.

To support proper cleaning and storage, the FDA has developed a new video on contact lens safety.  The video stresses the importance of emptying the solution out of the contact lens case after each use and using the rub-and-rinse method for added effectiveness.

Other important lens care tips include:

• Do not top off or reuse lens cleaning solution;
• Use a contact lens solution to clean, rinse, and then air dry contact lens cases after each use;
• Do not expose contact lenses or lens storage cases to any type of water or other non-sterile solutions.
• Replace your contact lens case at least every three (3) months

In early 2009, the FDA convened a workshop called “Microbiological Testing of Contact Lens Care Products,” in collaboration with several eye care professional groups, to develop consensus on test methods for evaluating contact lens solutions. Based on discussions from this workshop and from a 2008 meeting of the agency’s advisory panel for ophthalmic devices, the FDA is developing manufacturer guidance on potential labeling improvements for these products.

In its June 2008 meeting, the advisory panel for ophthalmic devices made specific recommendations for contact lens product labeling and directions for use, including adding a discard date on their products, in addition to the usual expiration date. The discard date is the date the solution should be thrown out after opening.

On May 19, 2009, the FDA’s Center for Devices and Radiological Health issued a letter to manufacturers of contact lens multipurpose solution products that include an option for cleaning without a step for rubbing the lenses. This letter informed these manufacturers of the panel’s conclusion that there is improvement in lens care when using a rub-and-rinse regimen as compared to a rinse-alone regimen, which omits the rubbing step. The direction to rub and rinse lenses, based on the advice of an eye care professional, has always been part of the labeling for multipurpose contact lens care products. More information on contact lens safety is available in a PDF.

Martha Stewart Discusses the Importance of Regular Eye Care

This is a good video where Martha Stewart discusses common topics in eye care including lazy eye, bifocal contact lenses, importance of eye exams for adults and for learning in children.