Reading a compensated Rx?

[Barry Santini]

Great thread. Barry get over the 12th thing life gets a whole lot easier when you just learn to accept that this is a common misnomer and move on.

I can't.
I can't.
I simply can't.


B

[leeopt]

[QUOTE=Barry Santini;497259]I can't.
I can't.
I simply can't.


O-U-Eighth-1-2?

[Y. Huang]

you can usually get a fairly good idea of the uncompensated RX in the frame if you hold it with the panto vertex and face form in mind in your lensometer

[tmorse]

I can't.
I can't.
I simply can't. B

+1

[CCGREEN]

[QUOTE=acesrwylde We then fit the patient with the appropriate measurements and send them to the optical that did their lenses. [/QUOTE]

Care to explain exactly what you are doing here? Your going to "fit" appropriate measurements? And then your going to send them away in hopes of someone redoing to your "appropriate measurements? And it work "every time"?
Until I understand this better it sounds to me like you are handing out warm fuzzy's and where ever the pt goes back to is just accommodating your expectations and the patients as they take the job and sit it on the "magic shelf" for a few days.

[Robert Martellaro]

you can usually get a fairly good idea of the uncompensated RX in the frame if you hold it with the panto vertex and face form in mind in your lensometer

Welcome to OB, Y.Huang.

You might find these tools interesting.

http://www.opticampus.com/tools/spectacle_optics.php

When we tilt an Rx lens in front our eyes, the spherical power increases, cylinder is induced with a sign equal to the sphere sign, with an axis of 180 for pantoscopic tilt, and an axis of 90 for dihedral/wrap tilt.

For example, a -6 D with ten degrees of panto tilt, with the OC at the pupil center, results in an effective power of about -6.25 -.25 x 180. To compensate, we would surface -5.75 -.25 x 90, or we can decenter the lens/OC 1mm below the pupil center/corneal reflex for every two degrees of panto tilt (Martin's Rule), aligning the optical axis with the center of rotation of the eye, correcting for induced power and cylinder error.

We shouldn't decenter for wrap tilt due to the induced base in or out prism, instead, reduce the wrap to a generally inconsequential five degrees, or use a "position of wear" optimized design.