The inspiration was this gap between conventional eyeglasses and self-refraction eyeglasses. My initial thought was that we could use fluid-filled eyeglasses as a refraction tool, but the issue went back to some training that I'd had as a young submariner back in 1986. Fluid at different altitudes and temperatures had different volumes, and if you lost a drop of it, or got an air bubble in there, there would be a calibration issue (this is very important on submarines, and also with prescriptions!). If your device is off by just a tiny bit - a quarter or even a half-diopter, you're going to get an incorrect pair of eyeglasses. One diopter is one millimeter of movement in the exact focal point of your lens. What a good lens is supposed to do is make the light meet at a specific point at the back of your retina, and that lens in your eye increases or decreases in size as you look closer or farther away. People that need eyeglasses need them because your lens in your eye is either too close or too far from your retina, the back of your eye.
So glasses correct that deficiency by moving the focal point back and forth, and a diopter is a unit of measurement for how far glasses move that focal point.
So we needed something that was always going to be calibrated, so when you determined what your prescriptive needs were, it had to be exactly the same as the snap together lens. So I came up with this in September 13, 2013, and from after dinner until midnight, I was sitting at my kitchen table drawing this thing out, maybe 4 hours I was done, I had it.
The way the Usee works is that the long lens bar has a full 12 diopter range. It goes from -6 to +6 diopters. So 0 is what a person with 20/20 sees - they need zero correction. Hyperopes need a positive range for distances, and Myopes need a negative lens (and this is the vast majority of people). So this system allows you to solve both near and far vision problems. The lens changes power as the patient turns the dial, and naturally moves the focal point across the retina - just like a pair of binoculars, it's very intuitive. I've put this on children and elderly people in the developing world, and regardless of age, they turn the wheel, their vision gets clear, and their eyebrows go up - that they can see clearly for the first time.
The colors and numbers on the side of the lens are super-simple. If you start talking "diopters" and "-1.5" that's going to complicate the issue and slow down the education process. What could be simpler than a color / number system? Red 1,2,3,4? So if a patient dials into a Green 2, you pull a Green bag with the number 2 on it, and snap that lens in. If they dial in a Red 4, you pull a Red bag with a number 4 on it, snap it in. You put the glasses on the patient, do a retest to make sure it works, and then you're done.
Every step I took to get this kit to where it is was asking how can it be simpler? So a community health worker with maybe one day of education on the system can be an effective distributor of eyeglasses. I have trained farmers with no formal education on how to do the system, and they've picked it up easily. It's practical, and if they can talk to someone, they can do it.