Enigma???

[Pete Hanlin]

As you can see, I go through "spurts" when thinking about the practical aspects of optics. Now I'm reading an article in Vision Monday about the Enigma lenses- which have a 16 base curve. Are these going to be Rx-able? If so, what are the advantages of having a +16 base curve?

The article mentions a wider distortion-free field of view, so I take it they are Rx-able. Guess they'll have to be commercials like the Pontiac commercials (except these will say "Steeper is better...").

Pete

[Blake]

It said they would be available for -1.00 to +4.00 single vision, at least initially. It'll be interesting to see how they turn out...

Blake

[Pete Hanlin]

I've always been a fan of higher base curves, but WOW! It will be interesting to see how it works out. Since the lenses curve so much, I imagine the angle of incidence in the periphery will be more perpendicular (plus the fact that the "bad" portion of the lens will get tucked behind the peripheral vision of the patient).

Pretty neat stuff any way you look at it...

Pete

[Darryl Meister]

Originally posted by Pete Hanlin:
Since the lenses curve so much, I imagine the angle of incidence in the periphery will be more perpendicular (plus the fact that the "bad" portion of the lens will get tucked behind the peripheral vision of the patient).

You are right on the money, Pete. These "contoured" lenses have a nominal curvature that is roughly equal to the curve described by the eye as it rotates behind the lens at its vertex distance. Consequently, the vertex distance from the lens remains relatively constant as the eye rotates behind it, and the line of sight remains more orthogonal to the lens -- even at highly oblique angles of view.

The result can be quite impressive. In addition to excellent peripheral clarity, both distortion (the bending of lines and such) and chromatic aberration are significantly reduced with these steeply curved lenses. This is particularly beneficial, since Enigma is available in polycarbonate. Minus-powered Engima lenses also minify less than conventional spectacle lenses.

I believe that SOLA should have some technical papers on Enigma available very soon.

Best regards,
Darryl Meister
SOLA Technical Marketing

[Alan W]

Darryl
What do you perceive as a potential problem relative to lenses breaking under conventional head presures. Seems to me that even though these may be poly, isn't the risk of lenses snapping greater with lower powers or thicknesses and higher curves?

[JRS]

Conventional head pressures? Alan, are you referring to manufacturing?

[chip anderson]

Has someone re-inventied the origional Zeiss Puntal system perhaps?

[Darryl Meister]

Originally posted by Alan W:
Darryl
What do you perceive as a potential problem relative to lenses breaking under conventional head presures.

Hi Alan,

Actually, special edgers had to be designed for these lenses, since they are so steep. (I believe that there is also one or two patent applications in for this.) The angle of the bevel, for instance, was a big challenge. I'm not sure how much of an issue head pressue was, but I'm sure that they would have reduced it on the edgers if necessary.

Best regards,
Darryl

[Darryl Meister]

Originally posted by chip anderson:
Has someone re-inventied the origional Zeiss Puntal system perhaps?

No, the Zeiss Punktal lenses were designed with conventional best form "corrected curve" base curves, so they are much flatter than Engima.

For you opti-buffs, conventional corrected curve lenses follow the lower Ostwalt branch of Tscherning's ellipse -- while Enigma lenses are closer to the steeper Wollaston branch (which produces less distortion and chroma). If I remember correctly, Engima currently uses about a 16 D base curve. This is about 10 D than conventional plano lenses.

Best regards,
Darryl

[Alan W]

JRS
I'm sorry. I forgot to check back to this board. I was referring to edger head pressure and what settings will work best if selectable.

[Alan W]

Hi, Darryl
I really hope the concept flushes out in the field because it makes so much sense. It'll make a lot of people happy. As for the edger issue, I sense its time for change in that technology anyway. New lens, new finishing processing.
I have personally seen, although under highly experimental conditions, a dual beam YAG edger that does one cut/safety bevel/edge polish all in one rotation of the lens. A YG groover for the second rotation. I haven't the slightest idea about how the beam was controlled, but I have worked quite a bit with a YAG in prototypical work to create cliches for a new contact lens printing tech. Just happens to be in the hands of a major CL company that was part of the gobble fest last year.
I think lasers are around the corner, and if so, Enigma and all the generations to follow, may be the paradigm shift we need.

[Darryl Meister]

Hi Alan,

That seems like some neat technology... But just imagine that kind of power in the wrong hands! ;)

Best regards,
Darryl

[Alan W]

Yeh, I know.
I couldn't resist the temptation to see what it did to, like humans. When I did the CL coloration technology work . . .
I put the tip of my finger just next to the beam.
Uhhhh . . . don't do what I did. That was very stupid!
By the way . . I understand the CL coloration technology work I was part of was announced a few days ago by Ocular Science.
That's neat!

[Spexvet]

What ever happened to this lens?

[mrba]

Toast