Hey Guys/Gals
In your opinion which is better.... polycarbonate or high index lenses? Do they diminish peripheral vision for people with macular degeneration? Is the vision as good as with plastic lenses? Two different opticians have told my mother two different things, so we're looking for a tie-breaker.
Thanks & Have A Nice Day
Mark
I would suggest you give an idea of the RX. They are all plastic lenses and you will hear a hundred more opinions here. This is going to be like voting in Florida.Originally Posted by Hornfan
Chris,
Thanks for your help. I know nothing about perscriptions so I hope this makes sense to you because this is all I found.
Right Eye -- Dist. Sphere +2.50
CYL +0.75
Axis 020
ADD +2.50 (sphere)
Left Eye -- Dist. - Sphere +2.75
CYL +0.75
Axis 137
ADD +2.50 (sphere)
Vision is best in Glass.
Glass is the heaviest material there is and breaks more easily than any other material.
I second
You can see better through glass, however, my vote goes for Trivex.
I'm with jacque trivex is the answer.
There are still some variables that will require more stones to be turned over such as the size of your frame, fitting measurements (fitting height & PD) lens style (single vision, bifocal, progresive), lens manufacturer, and most important; is there is any potential of lens impact in the environment in which you will be using them?
Polycarbonate has a reputation of causing more periphial abberation (distortion) than other alternatives which becomes more evident in higher power lenses.Beware......Since Poly has a higher index than plastic it is technically a high index lens and therefore some places pass it off as high index material.
Modern high index materials also feature aspheric lens designs which afford a collateral benefit of improved optics for improved peripherial vision as well as cosmetic appeal. A competent optician should be able to take all these factors into consideration to compute the lens thickness you will recognize with all the mentioned alternatives.
Last edited by PAkev; 01-10-2005 at 06:36 PM.
Chip!
You forgot about RGPs!!
BTW Do you have lesser succes in fitting Hyperops than miops with RGPs or equal?
Lenny:
I did not forget RGP's. Chances of a happy patient with an Rx like this in any rigid lens are about 5% after an initial euphoric period if you get that. And actually vision is better with PMMA.
Chip
Thanks for a quick reply!
So Hyperops are much harder to fit?
Or you are refering to Presbyopic part of the rx?
Lenny:
Hyperopes are actually easier to fit. But a: the correction is low. B: most patients that have reached presbyopia and not worn contacts yet, fail (if they really cared about the cosmetics of contacts they would have tried them long before now. c: You already have a patient fretting about the optics of something he has never experienced (you know the type who feels he has re-searched something on the internet and actually thinks he knows something about the subject after he has done so) this does not bode well.
Lots of things bode bad signs. Patients who are looking forward to CL and willing to cancell thier other activities (even a hair dresser appointment) do well. Those who just work you in when they have the time do poorly. This patient gives me very bad vibes even as a spectacle customer, shudder to think how he would do in contacts.
Chip
Now rigid bifocals work well if you have a SV contact wearer who is tired of the reading glasses, but bifocals as a starting point, bad vibes.
Psst - Chip, he's still here.
If you can cut through the Cr** above, listen to me.
Polycarbonate will work fine. It's cheap, light, workable, and has built in UV. It comes in a huge variety of designs.
If your mom has ARM, she would do better with a stronger BF power, +3.00 or up, but that's up to your ophthalmologist. That means a trifocal is a good idea. Avoid progressives in this case. Try for aspheric, if available.
Glass is a ridiculous suggestion. That's like putting the world's best tires on a Yugo. Your mom's vision will not appreciate the difference of glass, but her nose will kill her.
drk
How is it that Chip, me, and a few million others are still alive after having worn photogray lenses in the 1970's, (double weight) in glass?
We survived because we knew how to adjust a frame properly on a face without the customer's nose suffering and giving him a reason for suicide.
Chris and drk:
I'm still wearing Photogrey and my nose is still like new.
Sorry to disagree.
I've been around long enough to know, even with the best possible adjustment, a plus Rx in glass is heavy and uncomfortable. It's lunacy to suggest it to an old lady with thin skin.
From the context of the original post, I believe the question was asking for opinions between two materials....... Polycarb & High Index. :finger:
Opinions are just a personal thought contribution, to be respected by those giving and taking them. :D
I would agree with drk on this... an old lady with thin skin is not a good choice for glass... even though its not a really strong script... i would reccomend plastic before glass in that case... of course having the patient in front of you is the best way to make a decision on things like this.. you can take into account frame size weight and fit into consideration...
If the frame is of average size a well surfaced plastic lens will do the job.
drk, we used to go the local eyeclinic were they did 10 cataracts a day for 3 days a week in the 1950's and 1960's to fit the patients with their first temporary glasses.
They were all pantoshape 42 to 44 eyesizes with glass lenses of +10.00 to +15.00. These people could see again and had heavy glasses on their noses. It was a rule to only sell metal frames becaause they could be adjusted properly.
These people were from the old generation with as you say "old lady with thin skin".
You just tend to forget that the optical trade has existed long before today's generation came along and did as good a job with much more primitive means as you people do today.
We had to learn to adjust and it was done properly and I can still do it and so can many of the older optical retailers.
Last edited by Chris Ryser; 01-11-2005 at 03:01 PM. Reason: I disagree ..........your disagreement
I appreciate all of the input and will pass along all your info.
No one mentioned aspheric designs yet :) so I'll make that recommendation. Polycarb is visually less perfect, but offers unparalled protection and with your moms condition I think that is a consideration worth weighing. The unfortunate here is that your moms vision will probably continue to deteriorate. There are several gadgets on the market that will give some help for her fading vision. Check out a local dispensary that specializes in low vision aids. You may find their input especially helpful. And forgive our overzealous responses. :D It comes with the turf in "opticland".
shutterbug
Don't use Aspheric designs if you have bad cornea, developing cataract, or macular degeneration. Don't use progessive (invisible) bifocals either for the above conditions. Vision is best through a plain old ordinary lens.
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