Prism question

[Iakwin]

Is it possible for a lab to do :

eg R) -4.00/-1.00x100 BI prism @ axis 20
L) -5.00/-2.00x70 BU prism @ axis 70

Or should we use the TAN/COS/SIN rule calculation, converting it, then send to the lab?

Just curious, as a fellow friend said it can be done in the former way...

[chip anderson]

Prism can be stated and ground at any axis, and this means 360 degrees around the clock, not just 0-180. Don't try to make things harder than they are.

Don't know why we got into the habit of stating complicated things like one up one out when 1 midway between the two is what is desired.

Chip

[HarryChiling]

I know the opticians I work with see the 1 up 1 out as the easy way of doing it. If I had to explain to them that prism has an axis their heads might explode.

[Jacqui]

I know the opticians I work with see the 1 up 1 out as the easy way of doing it. If I had to explain to them that prism has an axis their heads might explode.

Sounds like our competitors :D We see it both ways here and have found it's actually easier when the axis is given (probably because of our software).

:cheers:

[HarryChiling]

I agree it is easier for me as well, but I do have a lot of dispensing opticians with no lab experience. Oh and I am everybodys competitor, I want to be the best so watch out.

[shanbaum]

It's certainly easier to validate or determine in a lensmeter (at least, a non-computerized one) in polar form.

[Darryl Meister]

Keep in mind that prism is generally measured and prescribed using rectangular (horizontal/vertical) coordinates though.

Best regards,
Darryl

[Lee Prewitt]

Is it possible for a lab to do :

eg R) -4.00/-1.00x100 BI prism @ axis 20
L) -5.00/-2.00x70 BU prism @ axis 70

Or should we use the TAN/COS/SIN rule calculation, converting it, then send to the lab?

Just curious, as a fellow friend said it can be done in the former way...

I don't see how much prism is being ordered. So the answer to your question is no. Insufficient information.