Wenn do you gues start reccomned a thinner material.
A: 1.60
B: 1.67
C: 1.74
pleas we need an impartial judge in this matter,
so pleas let us know what you gues think i the right time to reccomend thinner lenses.
best regards
Peter
Wenn do you gues start reccomned a thinner material.
A: 1.60
B: 1.67
C: 1.74
pleas we need an impartial judge in this matter,
so pleas let us know what you gues think i the right time to reccomend thinner lenses.
best regards
Peter
Depends on the distance from the optical center to the farthest edge of the lens. To some it depends on how much the patient can be soaked for on the bill. Some wold eagerly put a -1.00 in 1.67
My rule of thumb below if patient desires and ecconomics do not effect.
-4.00 --6.00=1.60
and above I use 167.
On those cases that I have used 1.74 I haven't noticed any apprecible reduction in thickness but a sizable increase in the wholesale price.
Hope this helps with your "debat."
A quick trip to opticampus.com will usually settle it for us. A lot of times the upgrade in material isn't worth the cost or decrease in abbe.
For me it all depends on the A, B, ED, and PD measurements
Chip do you realy use 1.50 for -3.75 that sound strange in my ears but thank you for your anwser. what about + LEnses wenn do you start using 1.60
Originally Posted by Mr.Powers
That's not strange at all. It's all in the position of wear and the eyesize. I did a beautiful trivex job the other day:
OD -0.75 -2.00X 005
OS -5.00 -0.75X 140 Shamir Auto II SV in a 48 eye
Pt was thrilled and she didn't have to fork out beaucoup bucks for the high index stuff.
"Strictly speaking, there are no enlightened beings; only enlightened activity." -Shunryu Suzuki
I think the most important thing is ask how often a patient is going to be wearing the glasses. I do -4 through -8 often in poly (yes-ack-poly) if it's a patient who is wearing contacts 90% of the time.
I also do plastic very often in jobs that are low power with a lot of cyl, say +/-.50 with up to a 3 cyl. If I'm concerned about the thickness of plus powers, I'll indicate for aspheric.
Most often though, for folks that don't wear contacts, I break it down like this:
2D and under (except for drills and groved)- CR39
2-4ish- Trivex or Poly or 1.60 (depends on the lab)
5-8ish sometimes 1.67 or
6 and above- 1st check and see what is available, then we start talking about the differences that COULD occur with a 1.70/1.74 and if they want to spend the extra money and possibly the extra wait.
There are of course exceptions to everyone of my rules, as they are not really rules but my guidelines. It's been a long time since I've had an apprentice, but if I had one, this is how I would begin the 'what material to use' training.
Don't forget: include weight of lens, and monocular acuity ......should be included in your "formula" for index determination.
Eyes wide open
looks like the same debate we have i do like optilady and one of the others do like chip
Weight of the lens is big and has to be accounted for in the frame and how well that weight will be distributed. I put my father-in-law in a +0.50sph-4.25 cyl cr39 lenses and one frame carried it very well and the other had to be remade to trivex, both were comparable in size. We have -4.00 samples in an exaggerated eye-size to give patients and idea of what the possibilities are.
How come nobody is trying to find out what a "debat" is? Dingbats, I know about, debats, no.
Debate !
Mr. Cheap ( points ) Anderson
I will bet that my English is better than your Danish, or maybe not, you got a Danish sir name.
Best regards
Peter
Here is the basic ranges I recommend. Plus powers benefit from an Aspheric High Index lens faster than minus due to Vogel's rule.
1.50: +1.50 to plano, to -2.00
Trivex: +2.00 to plano, to -2.50
1.60 asph: +3.00 to plano, to -4.00
1.67 asph: +4.50 to + 3.00, -3.00 to -6.00 (low ABBE on 1.67)
1.74 asph: +4.00 and up. -5.00 and up.
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