How to calculate base curve radius

**kekkec** · 02-15-2013, 06:18 AM

Hey everyone!

I'm new to this forum but since it looks like a great source of info I might stay a while :) Anyway, I have a question for any skilled optician. Long story short, I'm trying to design my own sunglasses but in order to do this I need to know the radius of different base curves for sunlens. Unfortunately I don't have much knowledge from this field which is why I was hoping you could help me. Also do you think it would be more appropriate to post in ''professional'' part of this forum? I chose to post this question here because I'm not qualified eyecare professional.

Thanks in advance!

**SharonB** · 02-15-2013, 07:39 AM

Originally Posted by kekkec

Hey everyone!

I'm new to this forum but since it looks like a great source of info I might stay a while :) Anyway, I have a question for any skilled optician. Long story short, I'm trying to design my own sunglasses but in order to do this I need to know the radius of different base curves for sunlens. Unfortunately I don't have much knowledge from this field which is why I was hoping you could help me. Also do you think it would be more appropriate to post in ''professional'' part of this forum? I chose to post this question here because I'm not qualified eyecare professional.

Thanks in advance!

Your answer lies within the question - as you are not an optical professional, then why not consult one locally? There is also not enough information here to give you an answer. Rx? Non-Rx? Conventionally surfaced? Digitally surfaced? And why are YOU designing them? Also - Google is your friend.

**kekkec** · 02-15-2013, 08:36 AM

Hey Sharon!
Thanks for taking time to reply. To answer your questions - I like to make things by myself so one day I decided to try to make a pair of sunglasses. I went to a local optician but he either didn't know or didn't care enough to answer my question. However he gave me full support with cutting the lens according to my plans as long as I know which base curve. In order for lens to fit in my frame I need to know the radius of different base curves or how to calculate it. Anyway I'm interested only in Non-Rx lens, the most commonly used type (I guess that would be conventionally surfaced?). I tried to google this before I came here but I didn't find what I was looking for. I would love to give you and additional information you need and would really appreciate if you could help me with this.

**MikeAurelius** · 02-15-2013, 10:14 AM

It's a very basic standardized formula.

All measurements are in millimeters and based on the 1.530 index regardless of the actual material index.

To find the radius of a known base curve: (.53/base curve) * 1000

To find the base curve of a known radius: (.53/radius) * 1000

Again, actual index of refraction of the material being used is meaningless for your needs, as all lenses use a standardized base curve marking system based on 1.53 index tooling.

**CCGREEN** · 02-15-2013, 10:42 AM

I want to know how Keokuk came to acquire such a desire? Did he/she POOF! wake up one morning with a sudden epiphany, Oh my I want to make a pair of sunglasses. I have no direction with this. I'm just wondering to myself, What the hell?

**MikeAurelius** · 02-15-2013, 10:50 AM

Originally Posted by CCGREEN

I want to know how Keokuk came to acquire such a desire? Did he/she POOF! wake up one morning with a sudden epiphany, Oh my I want to make a pair of sunglasses. I have no direction with this. I'm just wondering to myself, What the hell?

Why worry about it? I know a lot of inquisitive people who simply like to make things and for some of them, making a frame is not beyond their abilities. I think he/she should be applauded for ingenuity and the willingness to experiment. And maybe this is the beginning of a company to make eyeglass frames.

**kekkec** · 02-15-2013, 12:18 PM

@Mike: Thanks a lot for your help. Your answer was all I needed - short and easy to understand even for an amateur like me.

@CCGREEN: It was very similar as you described it, except the *poof* happened in the middle of the day and not when I woke up. Big difference :)

**SharonB** · 02-15-2013, 03:09 PM

Just do a 6D base curve. Unless you are trying to edge "wrap" lenses into a highly curved frame, this should work. Good luck!

**shiyonghe1982** · 02-21-2013, 09:04 AM

As far as i know, There have a tool can gauge the lens base curve of the glasses lens and other material lens. Maybe you can look for that. Good luck!