0.25 cylinder change

by Jenny
(Dexter, MO)

Q: I'm a little frustrated because it has taken me 5 eye doctor (3 different doctors) visits in 3 years to get this close to a good prescription. Now, I am confused on a change the newest doctor wants to make.

One of my eyes has an astigmatism and is also a lazy eye. My last pair of glasses were the sharpest I have EVER had - however the lenses were mis-matched in strength a very little bit. The left eye focussed sharpest a few inches further away than the right eye (readers). They were fairly useful but a bit annoying due to the distance mismatch. When I would close one eye or the other, I could tell the prescription for each eye was super sharp compared to anything I'd previously worn - so I knew it was a simple problem of the sphere numbers. I never saw so much detail with my left eye in my life.

The sharpness increase that I was getting with my left I is attributed to that doctor prescribing me a 1.0 cylinder value. All previous doctors tried to give me a .75 cylinder. I know it doesn't sound like much, but it is night and day difference when I try on all my other eyeglasses.

So -- the problem: Yesterday my new eye doctor agreed that the sphere values were not quite matched between my lenses. She agreed to fix that - but leave the rest of my prescription alone. When I got home however I realized that she DID change more than the sphere value - she changed the cylinder value down to .75 instead of 1.0.

When I called her about this she said to just buy the .75 cylinder glasses and wear them for a while. Then if I don't like them she'll rewrite the prescription and I can BUY more eyeglasses for the 1.0 cylinder.

I don't want to have to buy a set of glasses to test. I want to know before I part with my money. I've bought 5 sets of glasses in 3 years (actually more than 5 - I got multiple pairs for reading, computer, and driving!) - and I'm sick of throwing money away.

So I need to know how to fix this. She wrote a RX for .75 cylinder - I want 1.0 cylinder. I want to make sure the sphere strength she indicated that will cause my focus to match between my lenses is preserved though. So, when I change the cylinder by .25 - do I need to deduct anything from the sphere value in the RX the doctor wrote?

She wrote:

+2 /+.75 /+091 (I want a 1.0 cylinder though)

Would I order:

+2 / +1 / +091

Or would I order:

(1.75 (or?) / +1 / +091

All I wanted was for the sphere value to be adjusted. I did not want the cylinder to change. I'm super sensitive to changes, I use my glasses for art work and very detailed projects. .25 sounds trivial to some - but it isn't trivial to me.

Thank you.

A: Hello Jenny,

I have to agree that is frustrating that you cannot have what you need ...

First things first.
I had this situation with a client of mine who was telling me how big difference is between the old and the new eyeglasses, even if I changed only 0.25 diopters.

So I know that some people feel any small differences, and you can change the vision with the most insignificant changes. I do not understand why you had so many doctors, consultations and eyeglasses before the final and good pair of glasses, usually one consultation is enough.

About the diopters, I think that if you have the best vision with 1.00 cylinder, you should keep that. I don't see any reason to go back to 0.75. The sphere part is a different part of the prescription; you should adjust it only after you put the 1.00 cylinder and see which gives you the best vision.

1.75 or 2.00 is a question of comfort and clear vision. My idea is to go back to this doctor and try on the both versions ( both with 1.00 cylinder) and only then make the glasses. I do not agree with buying test lenses and then another pair if the test is no good. As long as the doctor has lenses to try on at the consultation room, you don't need to spend money on it. The idea is to buy one good pair of eyeglasses, not to try different glasses with your money.

In the end, I see that you have different glasses for various activities, can I suggest you the progressive lenses? They solve all your problems and is one pair of glasses to wear all the time.

Hope this helps,

Comments for 0.25 cylinder change

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Dec 27, 2016
Thank you for posting this
by: Patrick

I am also having trouble finding lenses that do not cause strain. And these eye doctors say, .25 cylinder change is nominal. or a 5 degree axis change is not very much. I want to most accurate lenses possible. Any strain takes away from productivity. I can tell a huge difference with different cylindrical power of .25. Yet I call the doctor and they are like that is a minimal change. I feel so unvalidated.

I sit at a computer for hours a day analyzing text. That is very different from watching a video or just browsing.

I am having to order lenses to test them out. its a huge bummer. I have been through three lenses already, I did not order a coating on two them and the 1ones that do have a coating have a prism that is too strong. I can not believe the eye industry is in this state when we are all so dependent at looking at screens all day for our work. at least for me. be well.

Oct 13, 2017
Inaccuracy in Spectacles power (prescription for bifocal lenses)
by: Anonymous

1. The opthalmic doctor ought to show much patience while trying different power of spectacle lenses, for each lens parameter - sphere, cylinder & esp. the axis - which ofcourse is progressive.In practice, patience exerted by opthalmic doctor is far lesser then the desired - infact is is often seenthe nonpreference of the doctors to the act of trying the lens power - all of them prefer other treatment of the eye.
Axis of the lens to be arrived correctly, needs more slower & precise controlled trial of the lens - progressive rotationat different angles. However, this is seldom done, with the lethargy at the cost of serious eye strain of the patient.

2. I have had the experience, wherein after strong physical eye pain on using for a week, the newly prescribed & made glasses, the opthalmic doctor then advised a change in the cylinder from plus, to minus. Both the glasses, plus cylinder and aswell as the minus cylinder, vision is OK. I am still in a fix, uncertain on how to proceed further with such a major change.
Can such a change in lenses cylinder power from plus to minus be needed ?

Oct 28, 2017
Answer - Inaccuracy in Spectacles power (prescription for bifocal lenses)
by: Arpi

As we explained on our site, the lenses for astigmatism can be written 2 ways: with (+) cylinder or with (-) cylinder, depends on the prescription or optical shop.

For example :
+1.00 sph / -2.00 cylinder 90 ax can be written
-1.00 sph / +2.00 cylinder 0 ax

These two are the same, is only a convention to describe the lenses for the optician.

So, if you see well with both prescription is because are the same or very close, but written differently.

So I think is no need to worry about big changes, is just written differently.

To check this, look at your old prescription and ask the optician to write your new prescription with the same cylinder sign as the old one, then compare them.

I think you will see there are few differences.

Hope this helps.

Jun 28, 2018
+ and - of Cylinder values
by: Anonymous

My understanding is that in the "old" days cylinders were ground on the "inside/convex/rear" side of the lens and was designated with a + sign. In todays "modern" world the cylinder in ground on the "outside/concave/front" side of the lens and are designated with a -. There are "converter" tables to convert the "old" to the "new" on the "net.

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