chromatic dragons in my lens

[chaoticneutral]

Hey there optiboard goers, Id like to pick your brains once again cause there so tastey. I have a patient who has a realativly big eyesize (52) 1.67 lens with crizal saphire thats complaining about chromatic abberition in the lens at the peripherie. I can see what shes talking about, if you look theres a yellow color shift aura around objects, and yes I know that a higher abbe value and of course a smaller eyesize but wait theres also The difference between the index of the AR and the index of the lens. All that aside, do you think a smaller eyesize with a digital lens and maybe some base curve matching with a trivex lens and a crizal saphire for the index matching will reduce the chromatic abberition the patient is experiencing? THanks

[mshimp]

What is the RX? 52 eye isn't that large. SV, PAL, or FT?

[drk]

Sure it would. You are contemplating the nuclear option.

[other_bill_fea]

1) As other posters have said, what's the Rx?

2) As a wholesale lab, if you consider a 52 eye to be 'big'....I love you! No, really, I do.

3) You're going to have less chromatic aberration with Trivex than 1.67. The hard coat is going to be closer to a 1.53 index than a 1.67

4) Digital lenses are usually good, but again, depends on the Rx and lens requirements.

5) Why Crizal? There's other options. Unless you're comfortable using the Dark Side of the Force...

[erichwmack]

I dont think a digital lens will help much with the chromatic aberration and not on a 52 eye. Also the index of the AR must be different enough from the index of the substrate for the AR to work properly. So again I don't think the choice of AR is critical to your problem. You could try trivex but since we don't know the RX it could be bad choice and cause other aberrations. Have you checked the optical center/axis placement? If you move the center it is possible that the aberrating vertical peripheral will end up being cut out of the lenses. It won't help much on horizontal peripheral aberrations though.

[Tallboy]

yellow color aura VISIBLE when holding the lens far from your facesounds like newtonian rings from an AR hardcoat. I have never had that problem with sapphire. Maybe try another brand of AR, or avance instead? I've had that problem with some house a/rs before, but never with avance

[chaoticneutral]

OP here, Im off work today but ill give more specifics tomorrow morning when I get into work, thanks for responding I preciate it.

[Uilleann]

Has this patient ever actually worn spectacle lenses before?

ALL lens materials exhibit a degree of CA, though certain materials in certain Rxs, and certain frame shapes and fits will tend to show more than others. Looking through the periphery of ANY lens will create the phenomenon, so perhaps some instruction as to how to more properly and comfortably use spectacle lenses is in order? Also, certain patients will be more sensitive to it than others to further complicate the witches brew. Is the pt a habitual CL wearer most of the time? Never worn any correction before? Coming out of 40 year old glass lenses perhaps? Is their neck in a traction brace following a catastrophic moose related accident that disallows them turning their neck/head whatsoever to see things from the sides? Does this pt simply like to give everyone the 'sideways glance' out of habit?

[MikeAurelius]

Wait, what about the dragon?

[AngeHamm]

Summon Bahamut. He should take care of that pesky Chromatic Dragon.

[chaoticneutral]

Awesome all thankyou for the responses, so first off, I tried to get my boss to allow me to summon Bahamut but he wouldn't let me. Something about unleashing Megaflare unto the world worried him. The patient is a habitual contact lens wearer, but has not suffered from any moose related accidents but I do get the impression she gives that sideways glance at most folk. I think shes hypersensitive to this anomaly. Seriously, shes a -5.75 -50 ou and just a real pain, but I wouldn't be happy with my glasses if I saw something that bothered me. She brought in a frame that has a 39 eye and is round instead of the 52 rectangle she picked from the frame board. Im fairly confident that should resolve the problem but I have a terrible feeling that she's going to cancel the order on a third attempt to make her glasses regardless of the outcome. Maybe summoning Bahamt isn't such a bad idea.

[Robert Martellaro]

shes a -5.75 -50 ou

That's enough power to induce enough prism, that will create sufficient lateral chromatic aberration, to generate symptoms. To decrease symptoms without increasing thickness, switch to a less dispersive material, that is, refractive index 1.70. Fit optimally. Tell her that's the best that can be done at this level of thickness, in this universe. Consider 1.60 for even less dispersion, albeit slightly thicker. Hyper-sensitives may need Trivex or CR39. The habitual eyeglasses will provide guidance.

[MikeAurelius]

I usually rely on Cthulhu for my dragon banishment, but maybe that's just me.

[other_bill_fea]

I usually rely on Cthulhu for my dragon banishment, but maybe that's just me.

I thought Great Cthulhu preferred the route of slow, creeping insanity? A great, horrible creature with a cult of seemingly brainwashed followers, listening only to their god and rejecting reason and logic...

I think I'm seeing a few too many parallels with the optical industry. I'm scared.

[MikeAurelius]

I thought Great Cthulhu preferred the route of slow, creeping insanity? A great, horrible creature with a cult of seemingly brainwashed followers, listening only to their god and rejecting reason and logic...

Yes, we do. That's the best way of banishing a dragon: driving the seer insane.

I think I'm seeing a few too many parallels with the optical industry. I'm scared.

Didn't you know that Lovecraft was a secret optician?

[chaoticneutral]

Thankyou all for understanding my madness, it makes my day much brighter, it conquers half my bosoms sadness, and makes my soul much lighter.

[kentmitchell1961]

Then our job here is done........

[Fleming]

I haven't been on the board in some time. I have to say that was the best and most interestingly funny thread I have read in some time. Good job.