Lately, there has been a lot of enthusiasm in the ophthalmic industry about coatings and topical applications that prevent lenses from fogging up. We asked one our favorite coating experts, Michael Bellomo of Opticote to write a guest post for us on the subject of fog free lenses and why does fog free matter? Eye Want to Know….Here it is, we learned more about the different types of fog free lens treatments and think you will find it interesting:
Q:Is the current enthusiasm in the ophthalmic industry about coatings and topical applications that prevent lenses from fogging up a good thing?
A: At one time or another, consumers from all walks of life who are dependent on glasses encounter what I refer to as the ”white wall”. For some, this occurrence may be a minor inconvenience. For others, depending on their activity, the constancy and immediacy of their vision at all times simply can’t be conceded. No one wants to injure themselves or those around them. As such, I think we can all agree; when your vision is compromised, your safety and that of those around you is in jeopardy.
Fogging on lenses is caused when there is an imbalance between the air temperature and relative humidity. This occurs on warm days as well as cold days. The imbalance causes water vapor molecules to form on lenses at a molecular level. When enough of these vapor molecules coalesce together, they form an opaque film over the lenses resulting in a blinding effect that can render an individual motionless anywhere from 30, 60, 90 seconds or longer. When it comes to unanticipated occurrences, a lot can happen in a matter of seconds.
Modern chemistry has developed a product that has hydrophilic properties. From an ophthalmic perspective, a hydrophilic application prevents the build-up of water vapor molecules on a lens. In turn, this prevents an opaque film from forming on a lens. (This application is not to be confused with a hydrophobic coating which causes water to bead up on a lens for easy cleaning but does not prevent them from fogging up.) Today two methods of hydrophilic application are available. Several resources have a topical application available that is applied using a towelette or a liquid in a small bottle. Both are wiped onto a lens and according to many do prevent fogging. However, one must be aware that re-application is required when performance degrades.
Opticote took a different approach to creating a fog free solution. Over four years ago, a leading Rx safety supplier reached out and asked Opticote to develop a permanent fog free coating. The result is an application by which lenses receive a two-step coating. Uncut semi-finished lenses are dipped into a hard coat primer which is then thermally cured. This hard coat primer is an integral part of the process as the fog free solution needs to bond with the surface of the lens. After the initial cure cycle is completed, the lenses are then dipped into the fog free coating solution and for a second time and are then thermally cured. The result in an application that is permanent.
In today’s society, eyewear that fogs is more than a nagging problem or inconvenience. With the cost of insurance spiraling, workplace safety, to include eyewear, has become of much greater concern. As well, active consumers have raised the bar when it comes to spending money and with that, they have raised their expectations when it comes to service providers having solutions for their needs. Opticians are not exempt!
Whether asking the question or being asked the question, the key is to be educated about the applications that respond to the issue of fog free solutions under a variety of conditions. Whether those conditions occur in the customer’s work or active lifestyle, having the answers is key to breaking down the “wall”.