How does Free-form chalenge us?
Consider this RX, as written...
R -6.00 - 2.00 x 45 2 base IN
L -3.00 -2.00 x 135
Add + 2.00
"Please dispense progressives"
Signed: Joe Blogs MD
So you think about it...
Clearly the patient is:
Just about aneisometropic, has oblique cyls, and is a moderate myope
A discussion with the patient confirms the need for a multi-purpose pair of spectacles - he works in a shop, selling computers, typing up orders, and serving customers all day long, and often multitasks
In the first instance, this looks like a perfect example of a RX for free-form progressives, where the free-form optimisation, can go some way to alliviating some of the problems this type of RX poses
What do we do next? What other info do we need from the practitioner, who is not in the building?
So eagerly we run off and (for no other reason than its the first one to come to my mind) grab that ILT order pad the Rodenstock rep left behind
It asks you for
- Test BVD
- The order and power of the lenses in the trial frame including the prisms
- How you want the prism split up
- How much the patient converges
and
- The dihedral angle of the frame
- Frontal angle
- BVD for the dispensed frame
- Mono OC's
- Mono Heights
Now we are stuck. To start off with (to my mind) the BVD ought to have been on the original order. The other information (to do with the test) is not available. How many "regular dispensers" would struggle with the dispensing measurements.. the implication on the form, is that they want them pretty accuratally
The industry as a whole is not set up to deal with this sort of free-form technology - and thats pre-order. This technology is what we all have, available in our practices today, and it is allready being "demanded" by patients. Some are calling them the "ultimate lenses", but at the moment, unless the refractionist is doing the whole job "from refraction to dispensing and ordering", or, if the dispenser is working hand and glove with the refractionist... the process stops
what practitioners need to do is start recording this type of information, if they have a slight idea that this sort of lens may be used in the dispensing. what dispensers will need to do is learn how to measure all of the new measurements (that most) dont ever measure for anything
The lens manufacturers are throwing down a chalenge to us
How do you order a Freeform lens?
First all freeform technologies do not need the same information.
My company has developed freeform designs. We are currently developing more and to handle the ease of use for the optiician we are requiring the frame be either one of ours (ICE-TECH), or to send any other frame to us at ICE-TECH Rx. Our remommendation is to dot the pupil and submit the standard Rx. We measure the frame, make the necessary calculations and will return the completed frame and lens ready for delivery to the patient.
Some freeform designs do not require frame angle information making them not quite as individualized.
A good lens takes more than Freeform
Quote:
Originally Posted by QDO1
This is an interesting observation. It seems that Free-form is a catch-all type phrase, that describes a certian type of process - It does not however garuntee the quality of the result of the process is comparable between manufacturers or designs
The word "aspheric" is a similar word. everyone expects "aspheric lenses" to deliver "thinner lenses with superior vision", whereas Aspheric simply means "not spherical" - An aspheric lens could be thinner/thicker and/or with better/poorer optics
I am always a little wary when a new technology buzz word is touted as the "way to go" or the "latest best thing". I think the quality of a free-form lens is only as high as the quality of the information (measurements etc.) supplied in conjunction with the quality of the algorythm generating the final design
You have nailed the point I was trying to make. In addition to having any piece of equipment it is necessary to have skilled operators.
With computers driving the lens manufacturing; freeform machines the operator of the CNC freeform machine, is to a large degree, the lens data generated that software. This software now becomes the operator of the machine. (The actual loading of the lens into the machine to make the lens is even automated in many cases.) "No humans needed here". Where great humans are needed in the process, is in the data entry and the software design and development. The final skilled human needed is the fitting optician. The optician is needed to make sure the fame is properly adjusted and the patient knows how to use the product being fitted.
Physio & 360 Explaned? Plus a few questions
Thanks Pete for the information about the Physio and the 360.
I can now understand the marketing of the Physio. What your company is claiming is that the mold quality is digitally controlled. This is the same basic approach to making a freeform lens on the fly.
The fact is digitally controlled molds for progressives is not new technology. Many progressive designs are made with digetally controlled mold equipment. The main difference in the equipment is the time needed to cut a progressive metal mold is hours not minutes.
It is back to the design of the lens that is important. For example I would like to know how many different combinations of prescriptions are available for the Physio and how many for the 360.
In general there are about 1/2 million combinations of Rx's I would guess for the the front cast lens and for the 360 back freeform I would guess their are almost 1 million or possibly more.
These numbers are just a guess since I have not seen how many blanks are offered nor do I have the rx ranges available.
I think we all get *lost* in the discussion of free-form...
and forget that (currently) refraction technology and methodology lags WAY behind design and fabrication technology. I don't think we need even more precise technology in eyewear or lenses or measurements...
We need FAR better methods to deteremine the optimal refractive state (and use) for that patient.
Vision is fluid. Very precise technology(free form) is, in my opinion, not where we should be putting our efforts for better vision. A device that would be analogous to an "visual breathlizer" that would be adminstered at trafic accidents and police events would go a long way to getting the public to appreciate and demand better vision (products and methodology). But as long as local DMVs test acuity at such bare minimum thresholds and frequency (20/40 tested at 6 feet!!! and only once every *8* years!! in NY), there really is no need for the public to be really interested in better vision.
My 2 cents
Barry
Freeform lens designs and Refraction
Barry;
People are interested in better vision for more than passing a driving test. Yes refraction is next area that could use improvement. I saw a new piece of equipment that can do the refraction, a wavefront measurement as well as all other functions needed to check persons eyesight. This technology is not yet on the market, but will go a long way to producing better prescription numbers. It is a truely all in one machine.
I think in the future using a combination of new refraction technology and freeform even better vision may be attaineded.
Remember freeform is not a lens design. A lens design using freeform such as the Seiko Succeed in very good progressive design with approximately 30% more visual area and it also eleminates all of the swim and sway associated with traditional progressives. This and a few other lenses will fit into a new catagory Super Premium Progressives. Yes they cost a little more but the patient actual can have substantially better vision.