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slackware
07-25-2005, 10:08 PM
hi folks,

i have a question. maybe you can help me with it or maybe not.

ok today i surfaced a pair of 3base 2add progressive lenses.

i believe the script was

-1.00 -3.50
-1.25 -4.50

when i looked under the lensometer, the right eye was perfect on power. when i went to go look at the left lens, it was on power, but one problem, there was a heckload of waves in the lens. is there a way to correct this? what i tried doing since it was a minus lens, i used the same lap and refined it for about 30 seconds to see if it would knock the wave out. turns out it increased the cyl power 50 more. i lowered the tool a quarter and a half diopter and it was on power again but still waves. it was a relatively small base cut like 3.62? but a high cross cut like 9 something. let me know asap if you have any suggestions. i ordered the lenses from an outside lab but i would like to try to correct this problem if i encounter it in the future.
the prism on both lenses were awesome. they are both at a half diopter down which is fine.

thanks.

OPTIDONN
07-26-2005, 08:19 AM
I hate waves more than anything in the world!!! It might be a few things. With the cyl power that high some computer programs have an option for elliptical error. This reduces the cyl power by around 6% or in the case of your powers .25 diopters. This decreases the 'fighting' and pad prematurly wearing between the lens and the lap. I also found it help full to crib the lens or cut it down to it's smallest effective diameter, total decentration x 2 + 2mm (this 2 mm gives you a little safety zone) + ED = minimum blank size. This will help eliminate the lip that is caused bu the high cyl.

HarryChiling
07-26-2005, 02:23 PM
make sure that your blocks are adequately chilled especially if you are using alloy. Also check the tempature of the water and slurry. My collegue Pete says to check the pads to make sure they were put on without any folds or problems since you only had the problem in one eye.