My computer glasses are about 1/2 my normal (distance) perscription. My "normal" progressives add about 1/2 (+1.50 diopters) to my distance prescription (about -4.00 dipters).
Also, one pair of progressives with the various add-ons can cost up to $450! I cannot afford to get new glasses each year. After paying $450, I started paing attention to ALL the numbers.
It turns out my miopia (nearsighted) perscription mostly stablized when I was in college, at about -4.00 diopters.
However, each year, my astigmatism (extra "cylinder" added or sutracted from one axis of the lens) axis tends to rotate to a different angle. This time, right eye is 147 (degrees), last time it was 143 (degrees). Its just enought to cause eyestrain and headaches.
If one had perfectly round lenses, one could simple rotate the lens to a new position in the frame, and use the same lenses for another year. This could continue until the actual perscription (diopters or cylinderr) change (which it hasn't for me for years).
Unfortunately, the reading perscription MUST stay in the same (lower half) orientation in the lens.
What if one arranged the perscription as two halves: One half the perscription with astigmtism compensation (computer glasses), and one half with progressive perscription? Alone, the computer glasses would still work like computer glasses (and provide astigmatism correction), and the progressives would provide close reading on the bottom, and (nearly) computer range on top. Together, the combined lenses would provide full distance and reading (or at least to tthe dashboard for driving) same as my regular glasses. In theory at least.
I got a new perscription from an actual eye doctor. I located a bunch of ultra cheap eyeglass sources on the web, and found perfectly round glasses. The only trick was setting the interpupil distance such that it landed in the exact center of the lenses.
[Pupil distance = lens diameter + bridge width]
I recieved my two pairs of round glasses, each with half my perscription as described above. The concept WORKS! All I need do is 3D print suitable frames to hold the progressive set as "clip-ons".
Further work must be done to minimize he dorkiness of having 3D printed clip-ons.