Edge Thickness

**Neophyte Optician** · 06-25-2012, 08:25 AM

I have two pairs of glasses. Both have the same prescription (-5.00 OU). Both are 1.67 aspheric. Both are in frames that are approximately the same size and shape. HOWEVER, one set of lenses are much thicker than the other. Why? How can I make sure the one that is so much thicker is as thin as the thinner one?

**J.P.** · 06-25-2012, 08:33 AM

Are the Frames the EXACT same pair?

Is so:

Sounds like maybe the PD's were cut differently, or maybe the Center Cut is thicker/thinner then the other. BC of the lenses may be different from each other.

If Not:

It can be a sizing or shape difference of the frames, and or the same as above as well.

**Judy Canty** · 06-25-2012, 09:06 AM

Remember, we work in millimeters and tenths of millimeters, so even a relatively small difference can have noticibly different results.

**gmc** · 06-25-2012, 09:20 AM

Originally Posted by Neophyte Optician

I have two pairs of glasses. Both have the same prescription (-5.00 OU). Both are 1.67 aspheric. Both are in frames that are approximately the same size and shape. HOWEVER, one set of lenses are much thicker than the other. Why? How can I make sure the one that is so much thicker is as thin as the thinner one?

If you have calipers, measure the center thickness of each pair. If one is significantly thicker and the frame parameters are close, there's the likely problem.

**Uncle Fester** · 06-25-2012, 11:57 AM

Plug the numbers into this site and see what it spits out-

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

If it's way off- as others said it's PD, center thickness, base curve or lens material not what you ordered.

**nicksims** · 06-26-2012, 11:13 PM

Perhaps one of the two sets was made with 1.0 CT stock lenses. Set #2 was a grinder?

**FVCCHRIS** · 06-27-2012, 11:43 AM

Originally Posted by Neophyte Optician

I have two pairs of glasses. Both have the same prescription (-5.00 OU). Both are 1.67 aspheric. Both are in frames that are approximately the same size and shape. HOWEVER, one set of lenses are much thicker than the other. Why? How can I make sure the one that is so much thicker is as thin as the thinner one?

Many good reasons listed and others not. We'll wait to hear your report on why they are different. A good practical exercise for a itty-bitty Optician! Good Luck.