Can anyone tell me when to prescribe single vision free form lens? What are the benefits? How does a single vision free form work?
Can anyone tell me when to prescribe single vision free form lens? What are the benefits? How does a single vision free form work?
You should contact Barry Santini and/or drk about this. They seem to be the most vocal about using them.
Here is some excellent information from Seiko on single vision Free Form.
http://seikoeyewear.com/Seiko/product.cfm?prodID=12
I've got a pair of their Free Form in SV and I've got vision just as clear at the temporal edge of the lens as I do in the center of the lens.
Seiko's SV is only available in 1.67, although Shamir's is available in all materials and works pretty much the same way. Patients with higher Rx's, +/- 4.00 or cylider over -2.00 will see the greatest benefit to the lenses, as it will elimiate the peripheral distortion they would normally get.
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
In general if I see an Rx with more than 1.50D of Cyl or a wrapped sunglass I will go FF. Anything less wont have that Wow! factor that the patient is looking for. My sunglasses are SV FF and there is a marked improvement.
- Optician
- Frame Maker/Designer
- Teacher of the art of crafting handmade eyewear.
agree !Originally Posted by kcount
i too do the same .......and it works really wow !
Is there SV freeform in polarized lens?
From Shamir...SV Autograph II Attitude
Shamir Autograph II Single Vision and Autograph II Single Vision Attitude (for Wrap frames) can be done with ANY and ALL materials, including all of the different color polarized from KBCo and Specialty lens, as well as Drivewear and SOLFX lenses..
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
Ice Tech AWTECH's lab can do SV FF in pretty much all lense types. I had a -17.50-7.00 done in poly trans for a pediatric pat. and it looked beautiful.
Clinton Tower
The intellect to live free is in short supply
ALT248=°
Can anyone give me the contact number for Ice Tech's lab? Thanks.
Send a PM to AWTECH here on optiboard, he's the owner.
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
Ice Tech 904-247-2627, you may even get Allen (AWTECH) when you call.
Clinton Tower
The intellect to live free is in short supply
ALT248=°
Yes, Cyls above 1D (or even 0.75D) are definites for me.
But, there is another, often overlooked factor:
With non-optimal pupil positions (very high above MC), even spherical powers and low cyls benefit from a well-designed free form.
Think narrower zyl frames, CL Rxs of -300 and above and high pupil heights. Using Shamir's Autograph SV FF moves the Rx sweet spot to a much better place than stock SV, with its OC placed at MC. Shamir includes prism thinning, something no stock aspheric and high pupil height placement can handle optimally. Combine this with an MR-8, abbe 42 resin, and watch the WOWs you get.
The CL wearer seems to exclaim the most with FF, since they had previously discounted that their eyewear would ever be as good as their contacts. They often arrive with their eyewear *on* during the day, and remark that they finally have eyewear acuity that rivals (or surpasses!) their CLs.
Could SV FF could possibly be the "silver bullet" that extinguishes the "vampiric" , nightime-only usage of CL wearers with their eyewear, i.e. "I only wear them at nite and in the early am"?
FWIW, SV FF now has captured 50% of my previous finished SV lens business.
Barry
Last edited by Barry Santini; 05-20-2010 at 06:28 AM.
Tried Essilor's SV flavor last summer. Mind you, I'm only: OD -1.50 -0.50 X 165 and OS -0.75 SPH. I noticed the difference. Moreso at night/low light, but it did feel slightly sharper to my eye. Not an amazing difference mind you, but it was noticeable. Just another 2 pence.
\Where the lenses poly or TRIVEX?
Old were poly - new were poly. Interestingly enough, the old Rx was a quarter stronger -sphere (all else same), but I still felt like vision was more crisp with the new Rx in the digital lens, particularly at night. Just my own impressions. :)
1-888-423-8324 its easy to remember that is 888-ICE-TECH or e-mail or PM me.
i just got some hoya nulux in 1.60. they are my first glasses that aren't poly, and i hate to admit, they were so clear that at first it was weird.
i hate pt's like me. i wanted to smack myself. it has taken me a good week so far to adjust, and i still sometimes feel like something is off. but the optics are certainly better off center. of course it could be because they aren't poly.
who knows.
they look fab though.
When to use SV FF lenses:
High Powers = Above +3.00 and Below -4.00 (changes to the design to fit the fitted vertex distance)
Moderate to High Cyls = 1.00 and above (both the primary and secondary meridians can be made to best form)
Oblique Cyls = 0.75 and above |15 @ 45 &
Significant changes from normal fitting philosopy =
The more changes from normal fitting philosophy then the more "precision" you are going to get from the lenses. Keep in mind you are offering precision in the optics. Now with that clarified anything that can potentialy reduce that precision can be added to the list.
- Fitted Vertex differs from Refracted Vertex =
- Increased or Decreased Panto = above 15 degrees (power compensated for effects of increased power and cylinder)
- Increased Dihedral or Faceform = above 5 degrees @ high powers | above 10 degrees @ lower powers (power and cylinder compensated for effects of increased power and cylinder, also compensated for any prism induced)
- Extreme Decentration = above 4mm per lens (reduce the amount of rotation necessary to reach the effective optical axis)
1st* HTML5 Tracer Software
1st Mac Compatible Tracer Software
1st Linux Compatible Tracer Software
*Dave at OptiVision has a web based tracer integration package that's awesome.
Harry's right (even though he hates me now...)When to use SV FF lenses:
High Powers = Above +3.00 and Below -4.00 (changes to the design to fit the fitted vertex distance)
Moderate to High Cyls = 1.00 and above (both the primary and secondary meridians can be made to best form)
Oblique Cyls = 0.75 and above |
Significant changes from normal fitting philosopy =
The more changes from normal fitting philosophy then the more "precision" you are going to get from the lenses. Keep in mind you are offering precision in the optics. Now with that clarified anything that can potentialy reduce that precision can be added to the list.
- Fitted Vertex differs from Refracted Vertex =
- Increased or Decreased Panto = above 15 degrees (power compensated for effects of increased power and cylinder)
- Increased Dihedral or Faceform = above 5 degrees @ high powers | above 10 degrees @ lower powers (power and cylinder compensated for effects of increased power and cylinder, also compensated for any prism induced)
- Extreme Decentration = above 4mm per lens (reduce the amount of rotation necessary to reach the effective optical axis)
When he refers to departures from "best form", keep in mind that it is not applied to just the more well-known base curves for 1.50 index, but also to the higher index materials as well. But keep in kind, all other thins being equal, that best form for a higher index than 1.50 CR 39 is always compartively *flatter*. However, don't ever rely on manyfacturer base curve charts, or finished lenses for determining the Best form Corrected curve. The whole industry has gone way, way way too flat over the last 20 or so years, in response to ECP and consumer demand. Yes, we've thrown out babay with the bath water, and been delivering horrible marginal optics in many cases.
This is an essential reason that even spherical wearers will benefit from SV FF lenses, since they probably wear lenses that have departed so much from Best Form.
FWIW
Barry
Doesn't everyone deserve SV FF??
Have used Autograph and Zeiss, and patients love them!
Carl Zeiss Vision also has a white paper available for Individual Single Vision, a customized free-form lens, at PersonalizedLens.com.
Darryl J. Meister, ABOM
Majeed
In India free form single vision and FF polarised are available. Free Form single vision can be defined as double sided aspheric lens. It will be thinner and flatter than normal aspheric lens. The distorsion at the periphery will be very less in a free form lens. It is very much suggested for plus powers and cylinder powers
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
Bookmarks