Posted by Jairo on 5/18/2019 to Progressive Lens Technology and Tips
Hi, Doris came by and she brought this frame, which she has had. It's her current prescription and she likes the lenses. She is just not happy with the frame. She wants me to put these lenses on this frame, which I sold her several years ago and it's still a beautiful frame. It's a Lindberg frame and they don't make it anymore. It has a very unique set up. It has two holes on each side. Two holes on this nasal edge and two holes on this temporal edge. The distance between each of these holes is 1.5 millimeters. So, we're going to keep the measurements from this set up (Lindberg Frame) and put the lenses in here. I've made a very bad drawing representation of what this shape looks like. Hmm, there is some resemblance and uh I know that the distance between these holes is going to be 1.5 so if we know the elevation of this one (hole), then we can just calculate and get that one (the top hole). The distance from here to the tangent line of this lens is going to be 23 millimeters high. And we're going to add one more, so that makes this one 1.5 more, it's going to be 24.5 millimeters in height for this one. We also know from here, this to the edge is going to be 2.0 millimeters.
The temporal edge going to be 2.0 millimeters away from the hole (bottom hole) and then the elevation to the tangent line is going to be 18 millimeters. Since we have that number, we just add 1.5 to that one and we get 19.5 (millimeters). I'm happy with that. Now, that we've done the math we have to disassemble this frame.
Step 2 in repurposing lenses onto a new chassis (frame) is going to be this one. We've already traced the lens. We've come up with accuracy of 1/100ths of millimeters. That is super accurate.
Giving you an idea as to what a millimeter is:
This is one millimeter. Now the accuracy in which we are doing these measurement is going to be 100 times smaller a millimeter.
We're making four holes 1.5 millimeters apart. If you look at this. Hole #1 is 2 millimeters away from the edge and the elevation 3.79 above the horizontal axis. Hole #2 is going to be 2.21 millimeters away from the edge at a height of 5.29 in elevation. Then we have hole #3. That one is 2.0 millimeters away from the edge and then hole #4 is going to be 2.15 millimeters away from the edge.
And it is 1.5 millimeters above the horizontal axis.
The angle at which we approach the perforation is going to matter greatly because the lens that we have right now is flatter than what we originally had. The angle at which we come in an perforate. This has already been perforated because this is the original lens that is on the frame. But now we're going to put in this lens onto the new chassis so we have to match the angle of incidence right here the angle of perforation to the curvature of this lens. So that is one thing that I had not talked about before but we're getting down to the nitty-gritty details. We have to match.
Regardless, of how much math I always do I run things as many times as I need in order to get it done perfect. So these are test lenses that I'm beginning with. Test, Test, Test. This is the final test product #1. Now I'm going to see if it works and if it works, then I'll run the final one, or if I have to make some tweeks, it could be diameter of the hole it could be anything then I'll run it as many times as I need to before I do the final cut. Test, Test, Test before you do the final product.
Great news, the first test run was actually really good and super close. Now the only adjustment that I have to make on the first test lens: the temple is slightly dipping and what I'm going to do is:
the top hole on the temporal edge, I'm going to push it more towards the edge so I can get this lift right here. That is all I have to do. Test, Test, Test.
And here we have the final product. We've got the temples closing really well. The measurements on the elevation of the bifocal are just right. This is called a drop temple, looks really good. Great glasses, that is what I can make for YOU.
Have a great day!