Human vision, medical??ask a doc...lenses...ask a lab!!

medical??ask a doc...lenses...ask a lab!!

Author	Message
SpecOPTI #1 / 8	medical??ask a doc...lenses...ask a lab!! i see alot of postings by alot of people that really don't seem to understand about the theory behind lenses...i don't get to drop by this group often but i would be more than willing to help out with any optical questions about lenses..... feel free to drop me a line anytime.......if its a medical question..please don't waste my time...i don't claim to be a doctor and i am not going to play an online doctor either!!!!ha ha jeff trail full spectrum inc/flagler optical (www.flagleroptical.com) ormond beach/flagler beach FL.
Fri, 19 Mar 1999 03:00:00 GMT

Raymond A. Chamberl #2 / 8	medical??ask a doc...lenses...ask a lab!! Quote: >i see alot of postings by alot of people that really don't seem to >understand about the theory behind lenses...i don't get to drop by this >group often but i would be more than willing to help out with any optical >questions about lenses..... > feel free to drop me a line anytime.......if its a medical >question..please don't waste my time...i don't claim to be a doctor and i >am not going to play an online doctor either!!!!ha ha When an honest lensmaker should stoop so low, well. . .the sun isn't about to raise in the morn anyhow, so we won't need another optical soul. Ray
Sat, 20 Mar 1999 03:00:00 GMT

William Stac #3 / 8	medical??ask a doc...lenses...ask a lab!! Here's one. What do you think of those lens molding systems as compared to normal surfacing? My guess is that theoretically you might get better optics in some powers, worse in others. Bill
Sat, 20 Mar 1999 03:00:00 GMT

Specs #4 / 8	medical??ask a doc...lenses...ask a lab!! Bill Quote: > What do you think of those lens molding systems as >compared to normal surfacing? My guess is that theoretically you might >get better optics in some powers, worse in others. well there are a few things that i saw that could be a minus as well as a plus.....and yes i did have them come by and demonstrate a few different systems. first...when grinding a lens i can place the optical center anyplace i like...so even if i am using a 70mm diameter blank, by using a prism ring i can move that OC any place i want so that 70mm now becomes a over size blank...while in casting you can not move that oc so you have to decenter each lens to get the pd you want...as well as move tthe oc....now the problems that causes?? well how do you match an OC if you are doing one lense?? if you can't than you wi;; get vertical imbalance...so doing one eye is out..... next...progressives..when i surface a progressive i use a process called prism thinning...this can't be done in a mold system...so you end up with alot thicker blank in the end than when you get surfaced product. as for prism..forget that..can't be done exspecially in low power lenses. now as for optics?? well acuity wise there isn't any differance...in fact if you get real precice the molded will be better than the surfaced...because its is a precasted power...that is if the factory mold is exact... the differance wouldn't be perceptable by the eye...and in fact you maynot even pick it up in a regular lensometer...in my riechart i can pick it up...it is usually in the 12ths...but i figure it is less than that...but i can't measure 6th's!!ha ha now...it depends on the person and what is available if you don't have a full lab...some people say its worth it...but for the price...well each person needs to do the math....i know of two doctors that got a system....one i end up doing about 60% of his work ...the other a little less..but he doesn't want to admit he made a mistake!!ha ha ha i could see a rural area needing one...but this being the computer age and faxes and all i would say...it would be alot cheaper to get a finishing lab(edger and blocker) and stock sv and finished bi-focals...and order the rest uncut...in most cases you get the lenses next day and you don't have to eat the boo boo's the lab does....they tell you how much you save...but{filter}up a few progressive and a few transitions and watch that profit drop!!ha ha i can say that the new systems are alot better than the first generation a wafer systems....maybe they will get the hang of it yet.... hope i was helpful........ jeff trail full spectrum inc/flagler optical ormond beach FL www.flagleroptical.com
Sun, 21 Mar 1999 03:00:00 GMT

William Stac #5 / 8	medical??ask a doc...lenses...ask a lab!! Quote: >while in casting you can not move that oc so you have to decenter >each lens to get the pd you want I wondered about that. It seems to me that they SHOULD offer a way to move the OC on a blank. Why can't they use prismatic rings in molding systems? Seems pretty straightforward to me... Quote: > next...progressives..when i surface a progressive i use a process >called prism thinning...this can't be done in a mold system...so you end >up with alot thicker blank in the end than when you get surfaced product. > as for prism..forget that..can't be done exspecially in low power >lenses. Same problem. No prism rings in molding??? Why not? (some molders might want to jump in here and give us a clue). Quote: > i can say that the new systems are alot better than the first generation >a wafer systems....maybe they will get the hang of it yet.... That's why I asked. Seems like they have a way to go yet... Bill
Mon, 22 Mar 1999 03:00:00 GMT

Specs #6 / 8	medical??ask a doc...lenses...ask a lab!! bill the reason they don't have a molded lens that has a decentered oc is that...they would have to have molds out the ying yang!!!ha ha ha....to expensive to have all the different molds for each need....just think of all the powers already available...than on top of that for each of those powers you would need molds for decenter right and left...that doubles it...than you need diffent degrees of decentration...that ought to tripple it or quadruple it....ARRRGGGG.... money talks..BS walks...know what i mean?? they want to keep it simple...and this way you have to buy bigger blanks to get the decentration more money mo money mo money!!!ha ha take care, jeff trail full spectrum inc
Mon, 22 Mar 1999 03:00:00 GMT

Raymond A. Chamberl #7 / 8	medical??ask a doc...lenses...ask a lab!! Quote: >bill > the reason they don't have a molded lens that has a decentered oc is >that...they would have to have molds out the ying yang!!!ha ha ha....to >expensive to have all the different molds for each need....just think of >all the powers already available...than on top of that for each of those >powers you would need molds for decenter right and left...that doubles >it...than you need diffent degrees of decentration...that ought to tripple >it or quadruple it....ARRRGGGG.... > money talks..BS walks...know what i mean?? > they want to keep it simple...and this way you have to buy bigger blanks >to get the decentration more money mo money mo money!!!ha ha Wait till I come out with my digitally reprogrammable lenses. Instant new eyes for 50 cents with a machine at the {filter}tore or free from your home PC! Let all those analog lens-flippers and -grinders sell their wares to museums. (Web) sight was meant to be free! ;-) Ray
Tue, 23 Mar 1999 03:00:00 GMT

steven robins #8 / 8	medical??ask a doc...lenses...ask a lab!! Quote: >Bill > first...when grinding a lens i can place the optical center anyplace i >like...so even if i am using a 70mm diameter blank, by using a prism ring >i can move that OC any place i want so that 70mm now becomes a over size >blank...while in casting you can not move that oc so you have to decenter >each lens to get the pd you want...as well as move tthe oc....now the >problems that causes?? well how do you match an OC if you are doing one >lense?? if you can't than you wi;; get vertical imbalance...so doing one >eye is out..... You can't move the OC on any meniscus lens because it does not lie on the lens surface. What you are moving is the major reference point ( MFP) of the lens.
Wed, 24 Mar 1999 03:00:00 GMT

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