I hope someone can help me determine if I'm calculating the adjustments to my prescription correctly.
I now realize that I almost never use my progressives for actual reading. When I'm reading a book or magazine I generally just take my glasses off, and for fine print I look over the top of the rims. But I use my new "computer glasses" (from Zenni, with the prescription calculated according to their site's instructions) all the time and love them. So it occurs to me that my ideal glasses would be progressives that go from my distance values to my computer values. But I want to confirm the calculation of the prescription. Zenni says this, but I find it confusing: "Multi-focal Computer/Desktop glasses – To create this modification, you simply split the Add number in half (if there is no equal division of the Add number, you’ll need to decide if you want your focus closer or further, and the quarter diopter difference will shift the depth of the focal plane, accordingly) and combine half of the Add with the Sph. The balance of the Add will stay in that data entry field." I don't understand why you would change the Sph if you want the distance part of the lens to stay the same. But I freely admit that I don't really understand this stuff. Here's my full prescription: OD-SPH: -2.00 OD-CYL: 0 OD-AXIS: 0 OD-ADD: +2.25 OS-SPH: -5.00 OS-CYL: +1.75 OS-AXIS: 10 OS-ADD: +2.25 What I *think* they're saying is to do this: OD-SPH: -.88 (1.12 + -2.00) OD-CYL: 0 OD-AXIS: 0 OD-ADD: 1.13 (balance of the ADD) OS-SPH: 3.88 (1.12 + -5.00) OS-CYL: 1.75 OS-AXIS: 10 OS-ADD: 1.13 (balance of the ADD) So would that result in glasses that are the same for distance, but with the bottom (reading) part optimized for computer (18-24")? BTW, here are the numbers that resulted in excellent computer glasses. I believe I had to round the SPH numbers to the nearest integers the Zenni form would accept. OD-SPH: -1.00 OD-CYL: 0 OD-AXIS: 0 OD-ADD: 0 OS-SPH: -4.00 OS-CYL: +1.75 OS-AXIS: 10 OS-ADD: 0 Thanks for any help! --~--~---------~--~----~------------~-------~--~----~ Check us out at the oft-updated http://www.glassyeyes.com! You received this message because you are subscribed to the Google Groups "GlassyEyes" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/glassyeyes?hl=en -~----------~----~----~----~------~----~------~--~---
