Double Concave Lenses ( Read ) | Physics | CK-12 Foundation
Double Concave Lenses ( Read ) | Physics | CK-12 Foundation
We have a new and improved read on this topic. Click here to view
We have moved all content for this concept to for better organization. Please update your bookmarks accordingly.
To better organize out content, we have unpublished this concept. This page will be removed in future.
Bi-Concave Lenses - OptiBoard Discussion Forums
Hey everyone,
I received a set of Nulux EP (Biaspheric) SV lenses from Hoya today. We use this lens a lot for our patients as we think FFSV is fantastic, but for the first time we have one lens that has a negative base curve on the front (-0.50). I've never come across this before, although I know of course that they are available and my understanding was that biconcave lenses are specifically for high minus prescriptions.
This Rx in particular was a R] -2.50/-2.75. The left eye was a higher minus but with less cyl and was surfaced on a positive base.
My questions are, a) would this affect the performance of the lenses
and b) why did they choose to use a -0.5 base only in the right eye.
Thanks for your help The frame was just a regular Bulgari, full metal... nothing special. Not particularly wide at all. PD was fairly central. Full Rx is as follows since requested.
R] -2.25/-2.75 x 46
L] -6.00/-2.50 x 168
Bear in mind these are Biaspheric digital lenses, and as such are always extremely flat. The off-axis optical performance of biconcave lenses is sub par to say the least, and the disparity between the left and right will likely make them unwearable for the patient.
If you want to see what kind of radial astigmatism and power error you're dealing with, go to opticampus and download a copy of Darryl Meister's Spectacle Optics program and run those numbers. Thanks Wes,
So, why did Hoya produce the job as such? Is it a mistake? As I said, we do dispense this lens a lot and have never received a negative front curve before.
Also, will the double-side freeform surfacing not amend the off-axis astigmatic error?
I received a set of Nulux EP (Biaspheric) SV lenses from Hoya today. We use this lens a lot for our patients as we think FFSV is fantastic, but for the first time we have one lens that has a negative base curve on the front (-0.50). I've never come across this before, although I know of course that they are available and my understanding was that biconcave lenses are specifically for high minus prescriptions.
This Rx in particular was a R] -2.50/-2.75. The left eye was a higher minus but with less cyl and was surfaced on a positive base.
My questions are, a) would this affect the performance of the lenses
and b) why did they choose to use a -0.5 base only in the right eye.
Thanks for your help The frame was just a regular Bulgari, full metal... nothing special. Not particularly wide at all. PD was fairly central. Full Rx is as follows since requested.
R] -2.25/-2.75 x 46
L] -6.00/-2.50 x 168
Bear in mind these are Biaspheric digital lenses, and as such are always extremely flat. The off-axis optical performance of biconcave lenses is sub par to say the least, and the disparity between the left and right will likely make them unwearable for the patient.
If you want to see what kind of radial astigmatism and power error you're dealing with, go to opticampus and download a copy of Darryl Meister's Spectacle Optics program and run those numbers. Thanks Wes,
So, why did Hoya produce the job as such? Is it a mistake? As I said, we do dispense this lens a lot and have never received a negative front curve before.
Also, will the double-side freeform surfacing not amend the off-axis astigmatic error?
If you are looking for more details, kindly visit double concave lens.
For more spherical lenses supplierinformation, please contact us. We will provide professional answers.
With competitive price and timely delivery, Hongsheng sincerely hope to be your supplier and partner.
Comments