Design Student with questions. Lens shape, edge width, bevels etc

**designstudent** · 12-08-2016, 05:22 AM

Dear OptiBoard,

I hope you don't mind me crashing this forum, and understand totally if I am ignored! :)

However, I am an Industrial Design Student in the UK, trying to find out information about lenses, cutting and specifically the shapes of lenses in 3D - as well as standard edge thicknesses and bevels.

I am currently undertaking a really interesting project to design an innovative new kind of spectacles frame, but it's difficult to find out information about lenses, if they are standard shapes when produced (uncut) and when you cut them, the thicknesses of the edges of the lenses and the standard bevels that are used by opticians/retailers etc. If there's a place online that I can see all the information a link would be most appreciated, standard searches have come up empty so far! :)

I am focussing on corrections from +6 to -6 at 0.25 increments.

As a 3D designer, I want to know if there is a standard set of lens moulds that are used across the board - if there is, then it makes my 3D modelling job on the frames far simpler! If I can anticipate standard curvature of lenses within my parameters (+6 to -6), then I can easily work out how to make the frame. I don't know if this information is "standard issue", though I do know that uncut lenses are generally made to the same size - which would lead me to believe there is a standard for lenses, as the shape must be the same to get specific corrections.

It seems to me that this should be the case, as when you go to get spectacles made - no matter what your correction, you have pretty much free choice of which frames you want! Or am I missing something?! Are there some techniques that I should know about that get around this and "squeeze" lenses into specific frames?

It might be that bevel shapes allow this, so that the edge of the lens is allowed to "overflow" the frame edge - but the bevel sticks into the groove in the frames.

Apologies for the rudimentary level of my questions, but I really want to find out more about the limitations of what I need to work with, so I can ace this project - and build a great product at the same time! :)

Thanks in advance for your help. Even if it's just a link to a great resource I'd be MOST appreciative!

DS!

**mervinek** · 12-08-2016, 09:08 AM

I would recommend you visit your local optical lab. They can explain and show you what you are asking.

**PRECISIONLAB** · 12-08-2016, 09:26 AM

I would contact software developer Robert Shanbaum as he is a optical guru who can provide formulas used in calculating lens curves, profile, thickness, etc and explain how lens shapes are generated and translated via trace files.

https://www.ocuco.com/

**CCGREEN** · 12-08-2016, 09:47 AM

The only thing "standard" in optical is that nothing is standard.
Every Rx, every lens, every lens material, every frame shape, every frame size and even down to how the pt wears the glasses on their face is different. Every item mentioned above affects the other to determine the final size, shape and thickness of the final product.
Maybe about the only thing that would be a "standard" would be our units of measurements. Millimeter and diopter.
Even then with today's newer equipment the measurements can be cut down to the 100th of a diopter, or a 1/4 or less of a millimeter, which for eyeglasses that slip slide and move around and the debate as to the current medical condition of the eye, can the person even perceive those hair splitting measurements?
Sometimes just cause we can do it does not mean that it needs to be done or that the patient would even benefit from doing it.
It is almost to the point to where stuff like that is more of a ego boost to those that get off on that kind of stuff. Or it just turns into a subject of debate for all the talking heads out there.

**Quince** · 12-08-2016, 11:43 AM

https://makeoptics.com/harrychiling/...ess-calculator

This is an amazing tool to get an idea of how a prescription lens will look in different frames with different fittings and different strengths. Obviously there are some key factors to flesh out before you can get any definitive readings, but this tool is very accurate if you have all the information to plug in. I hope Harry doesn't mind me recommending his calculator!

http://www.shorelens247.com/general/products.aspx

This is another approach you can take to get your more generic figures. These measurements are for the 'stock' or pre-prescribed lenses so they are not dependent on frame choice. You may need a little translating to read this properly, but most of it is straight forward.

Good luck!