Friday, February 17, 2006


DEFINITY Lenses use a revolutionary DUAL ADD design, to help you achieve your full vision potential. It is associated with a patented Free Form technology to optimize your prescription.

· DUAL ADD technology splits the add power between the front and back surfaces of the lens.

· This results in twice the surface area, which is used to create an offset design that delivers advanced optics.

Well hello again to my regular readers,
And welcome if this is your first time.

Obviously, in this post we are going to talk about the new Definity progressive lenses, but before we do, I would like to discuss some basics on progressive lenses in general.

First off, for those who don't know what a progressive is, the slang term that most people use, and are more familiar with is
No Line Bifocal.
But the proper term for this style of lens is Progressive.

When selecting a progressive lens it can be confusing because there are so many different styles of progressive lenses. It is like saying pickup truck, pickup truck is the style but you have Fords, Chevey’s, Dodge, Toyota, Nissan, Ect.
It is the same with progressive lenses there are many different styles but the style you get unless you're aware of this many times depends on where your buying your glasses, and what style that establishment likes to sell.

You might ask, what makes the difference?
Well each style has a different structure to the lens.
All progressive lenses have some sort of compromise that the consumer will have to deal with.
They all have some distortion or displacement somewhere in the lens design, any of you that have or are wearing progressive now know what I am talking about.
With most progressives, the biggest thing is you have to point your nose at what ever you are looking at.
You've heard the stories…… I can see great while I’m driving but have a little problem reading,
I can read great but I can't see very good in the distance.
And the biggest problem with all of them is in the intermediate.
People often complain that while on the computer or doing something else in that intermediate range that intermediate focal point is too narrow.

So that is some of the key factors to different styles of progressive lenses, for years all progressive lens manufacturers have been trying to develop smoother transitions between distance vision and near vision,
and have been trying to widen that intermediate area to make it more comfortable for intermediate tasks.
And that is the difference between a basic inexpensive progressive that you get at a discount optical versus a more expensive top-of-the-line progressive that you get in private practice or high-end boutiques.

So having said all that,
the new Definity as stated above uses a duel add design.
Instead of putting all the add power or the bifocal power on the front surface of the lens, they split it, and put some on the front surface and some on the back surface.
This, if I'm understanding correctly allows less distortion, a smoother transition between focal points, and a much wider intermediate area.

So for us old-time hardheaded lined- bifocal wearers that have not been able to adapt to a progressive lens in the past, we are supposed to be able to wear this particular style progressive without the inherent problems of other styles in the past.

I did get a coupon from my sales rep. At my Lab, and had myself a pair of polarized sunglasses made up with the new Definity lens.
And I have to admit it is a much wider intermediate then I ever tried before. And I am wearing them on a daily basis for driving.
I would like to get a clear pair now, and see how they are for my computer. I've seen so many new progressives come out over the years claiming to be the best and distortion free, and wider intermediate's, larger reading areas, and so on.
Some are very good, and some are junk.
But this new design does seem to make sense, so if there are any of you out there that have tried progressive lenses in the past and did not get along with them, you may want to try this new Definity lens, if you would like to know more about the Definity lens here is a Link:

As always, feel free to leave any comments, or ask any questions,
Hope this has been helpful, see you next time.