Bifocals Problem

by Tony
(Arizona)

Q: I've been wearing bifocals for about 3 years now and never had a problem until I got a new pair of glasses. I'll list my prescriptions and then explain the problem.

Original Prescription 2011: No problems with this prescription.

R: +1.00 -050 113 +150
L: +1.00 -025 090 +150
P.D.: 67.5

March 2014:

R: +1.25 -050 115 +175
L: +1.25 SPH +175 Axis was left blank on prescription
P.D.: 66.5

With this prescription I could see fine far away, but could not focus up close so they changed my prescription to the following.

April 2014:

R: +1.25 -050 115 +1.25
L: +1.25 SPH +1.25
P.D.: 66.5

Here is the problem I am having. I can see perfectly clear with my far vision, but anything up close doesn't focus clearly.

Here are some examples

If i'm trying to read, I have to hold the paper approx. 10 inches from my face to have the clearest vision, yet even that is not perfect. However, if I close my left eye I can see perfect through the readers at 10 inches, yet if I close my right eye I have to move the paper out to between 18 - 24 to see clear. Here is another example. I'm 5'9", I went to wash dishes and with both eyes open the dishes were blurry. If I closed my right eye they then came into focus. If I closed my left eye I needed to move my head to about 3" above the sink to see the dishes clearly. It seems that the reading part of my bifocals have monovision.

They have re-checked my eyes twice and I even took my bifocals to another eyeglass store to have them checked against the prescription, and the glasses matched the prescription.

I have never had any issues getting used to glasses and I can't believe that with such a small change I'm having this problem, and it's only with the reader part of the bifocal.

Even though the eyeglasses match the prescription, could there be a problem with the way they were cut? I can't figure this out and it's driving me crazy.

Just so you know with my original prescription I can see the same with both eyes or one eye closed.

If you have any suggestions I would appreciate it. The doctor is calling me on Monday, but I think they don't want to deal with it.

Thank you.

A: Hello

I must admit that your situation is really puzzling me.

The difference between the glasses diopters is too small to cause any problems. If you see well far away, that means the distance vision part of the prescription is valid, so we rule that out.

Let's see where can be the problem...

1. About the near vision area

If you must keep the book you read very close that means the diopters are too big for your eyes and if you have to keep the book away (far) to see fine, that means the diopters are too small.

In your case, you have both situations, so this means that the diopters are not the same for your eyes. Maybe there is a small difference between your eyes diopters, so they ignored it. I will go further and say that I think that you need a bigger diopter for your left eye. Being a (+) diopter and having a slight difference, you feel it only at close vision so no problem for the far vision.

2. The cutting part

It is true that mistakes can be made when cutting or mounting bifocal lenses, one of the most frequent is not mounting with the right interpupillary distance. This can cause discomfort.

For the first situation, I would recommend you a consultation with a different doctor or optometrist, maybe a retina consult and intraocularly pressure, a complete ophthalmology session looking for another possible condition that could cause a discomfort.

For the second, check your bifocal glasses not only for the right diopters, but for the interpupillary distance also.

If you have more questions, do not hesitate to ask and make a comment.