DIY Eyeglass Prescriptions

“Trying on”
the rimless
(Click for bigger)

I buy my glasses “off shore” and save a bundle. My progressives are $64.95. And my “computer/iron sight” glasses are $34.95. And that’s with “bells and whistles” added such as rimless frames and the better polycarbonate (for impact resistance).

I get them from an on-line eyeglasses manufacturer in China, I’ve been buying from them for several years and am very pleased with their product and especially their prices. You can even upload a “head shot” of yourself and then “try on” different frames.

I still have my eye exams done here in the US so there are a few extra steps when ordering glasses on-line instead of face-to-face.

First, let’s start with the prescription from the eye exam for a set of progressives. I will use that as a basis for one pair of progressives and one or more additional pairs of single-vision glasses for special purposes.

Seen to the right (and which you can “click” for a bigger version) is mine from about three weeks ago. It’s from the optometrist at my neighborhood Target store where I phoned and got an appointment in 30 minutes.

IMPORTANT NOTE: I take my old prescription in with me for the new exam. The optometrist should begin with that. (I’ve had two exams where that wasn’t done and found both to be unusable. For best results, I recommend you tell, don’t ask, the optometrist to begin the “which is better” process at that old prescription.)

Here’s that same prescription as above in a more legible format and with decimal points inserted as appropriate.

Eye Sph. Cyl. Axis Prism Base Add
O.D. (right) +2.25 -1.25 90  +2.00
O.S. (left) +2.25 DS  +2.00

You can get a full decoding of the abbreviations and units in this article at Wikipedia.

From my previous prescription, my “Sph” went up from +1.50 to +2.25 diopters. Since I’ve gotten older since my last examination, the lenses in my eyes have aged and need more “oomph” no matter where I’m looking, close or far. This measurement is the overall help my eyes need. In general, as we get older, this will increase.

I asked the optometrist if I really needed that much of an increase.

“Well,” he said, “I’ve written this prescription a bit stronger so you’ll be able to use the new glasses longer before needing to replace them. They may take a little getting-used-to. After you try them for a while, if it’s too much of a change, let me know and I’ll back this off a bit.”

I didn’t say anything but thought to myself that he probably thinks I’m ordering glasses here. But at the low prices I’ll actually be paying, I can start with a prescription I can wear now without needing to “get used to them,” And in a year or two, I can replace them with something stronger and still end up spending less.

Quietly I decided to try +2.00. That’s up from my previous +1.50 but less than his +2.25.

“What about computer glasses, Doc? How much should I add?”

“Well, you can use the progressives, the ‘near vision’ addition at the bottom will be correct.”

What he didn’t say is that if I take that “Add +2.00” and apply it to the whole lens, it all becomes “reading glasses.”

But he went on, “But for computer glasses, I would recommend only +150 instead of +200 since the computer is a little farther away.”

And while I hope to use this second pair for work at the computer, my real purpose was for shooting iron sights. For that, I’d need a tad weaker correction overall.

Factoring all that together, I decided to order the single vision “computer” and “iron sight” glasses with a +3.00 correction. (As you’ll read below, this would turn out to be enough for the computer and shooting, but might have been better at +3.25 or +3.50.)

One additional measurement is needed for the progressives, the distance between the pupils of the eyes. I presume the optometrist has the gizmo for this but since I already knew mine from an earlier visit to CostCo where they did the measurement just for the asking, I used that number again, 66.

A few hours later, I went on-line and ordered two pair of glasses.

Pair #1: Progressive lenses for general wear, frame# 367530, lense size/shape 225(W51,H32), polycarbonate

Eye Sph. Cyl. Axis Prism Base Add
O.D. (right) +2.00 -1.25 90 +2.00
O.S. (left) +2.00 0.00 +2.00

Pair #2: Computer/iron sight glasses (single vision), frame# 325611, polycarbonate

Eye Sph. Cyl. Axis Prism Base Add
O.D. (right) +3.00 -1.25 90
O.S. (left) +3.00 0.00

Here’s the finished order from Zenni’s website.

The new glasses arrived in a little over a week and I’m using them full-time now. The progressives are perfect — objects at a great distance are nice and sharp again and the reading “Add” is perfect for books and handwriting.

The computer glasses are fine for the computer (and front sight of my handguns) and usable for reading most things but at a slightly farther distance, say 24″ instead of 15″. That is, I have to hold the reading farther away with the “computer glasses” than I would normally. A bit more strength, perhaps +3.25 or even +3.50 instead of the +3.00 I ordered, might work but that would compromise the computer reading-distance that is otherwise very comfortable now. The computer and iron sight prescription is a compromise and the result is adequate for both uses.

Indeed, I’m finding that the computer glasses, with their “aviator” style big lenses, are perfect inside the office where I’m on the computer LCDs 36″ away most of the day. I will keep these on pretty much all day unless I go out when I’ll switch to the progressives. (I wear the progressives at lunch time when watching TV, etc.)

I’ve also found that the single-vision “computer” glasses are ideal when using hand tools and working around the house, such as when on my back under the kitchen sink.

If you’ve ever tried to do that — work under the sink — wearing progressives, you’ll know it just doesn’t work. Invariably, what you need to see will be at the top of your glasses where the progressives are set for infinity, not the 20″ to the bottom of the faucet that’s dripping. Single-vision glasses, on the other hand, have the entire glass set for that close-up distance so, whether you’re tightening a compression fitting, looking up to change a light bulb or doing any other “close up” job, those big full-size, fixed distance lenses are ideal.

(Next time a big plumbing job comes along, I’ll order an even stronger pair of single-vision lenses in Zenni’s cheapest frames. I’ll then have the perfect glasses for 20″ work and spend less than $20.)

Where others could easily spend $500 or more for two comparable pairs of glasses, I’ve got $400 left over for something else.

Will it be new faucets in the master bathroom, fancy tile on the kitchen back splash, or the first of several parts for an AR-15 kit?

Addendum 02/08/2013

I’ve found that progressives do not work well with the red dot sight — as I move my head while looking at the dot, it changes shape in a way that leaves me unsure of exactly where it is aimed. So I’ve started ordering a third pair with standard bi-focal lenses to wear with the red dot sight. The numbers needed for the Rx at Zenni Optical are already in the prescription so no additional information is needed.

Here’s a quick summary of the three pairs of glasses I get once I’m sure a new eye Rx is correct.

  1. I order a set of progressives for general wear throughout the day. These will be my “main” glasses. I spend a few extra bucks to make them nice. I prefer completely rimless but it’s worth adding that they tend to be less robust than those with a partial or full rim. I do *not* get the automatically darkening coating but will sometimes add the clip-on sunglasses for this style.
  2. I also order a set of computer or reading glasses with both lenses set, in their entirety, for work at the ends of my arms. I use these with iron sights but also find them extremely helpful when working on projects around the house.  Because anything close-up (arm distance) will be in focus no matter where it is in my vision, I find these are really nice to have for odd jobs such as screwing a hanging hook into the ceiling, laying on my back working under the sink, on top of a ladder hanging Christmas lights and so forth.
  3. And now I also order a pair of standard bi-focals, primarily for use with red dot sights but also as backups for the progressives in case they are misplaced.

From Zenni Optical, I can afford three pair of glasses.


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