Prism Thinning?

[bser]

WE NEED A LAB SECTION, BUT i WANT TO KNOW ? HOW MANY LABS USE PRISM THINNING ON PROGRESSIVE AND WHAT ARE THE STANDARD FOR USING IT (IE WHAT POWER AND ADDS}:shiner: AND CHILLED H2O FOR FINDER ?? HOW DO YOU USE IT & IS IT WORTH IT?? RECLAIMED OR FRESH?????

[shanbaum]

Stop shouting.

[eromitlab]

first. stop yelling. we can all read you fine at this size font... remember, we're mostly eyecare professionals here and we should be able to see clearly enough to read. ;)

second. prism thinning is commonly used on progressives to 'force' the eye down into the reading area (i notice it more on smaller frames with plus 'scrips), it used to be called 'yolk prism' or at least that's what I've been taught so far. I could be wrong. My lab sofware determines when to use it or not and I don't really see the need to know much more than why it's needed and how it works. color me lazy, I guess.

third. chilled water is good for a finer, probably best because it keeps the lenses and laps at a consistent temperature all day, and the blocking wax I use likes it too ;). Fresh is also a good option, but I don't have my machines set up that way. I find it easier to just recycle the water through (with about two tablespoons of Downy fabric softener to cut the foaming to nothing) and dump it at the end of the day. The chilling system consists of a reservoir of coolant (in my case, water) a pump, a chilling unit, about 30' of vinyl tubing and two copper tubes wound into coils that fit around the bottoms of my water/slurry pumps. it's just that simple.

[Joann Raytar]

Try this link in the OptiBoard File Directory:
http://www.optiboard.com/forums/showthread.php?t=12641

[eromitlab]

D'OH! I completely missed that one! Thanks for the help, Jo! :cheers:

[bser]

sorry about yelling !!!

[Darryl Meister]

Here is an article on prism-thinning: Prism-Thinning Progressive Lenses.

[eromitlab]

thanks for the link, Darryl! your other prism-thinning article that Jo linked to really cleared up my mis-conceptions.