Module 20 Section 1

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Module 20:

Section 1:

For most patients with a significant glasses correction, having comfortable glasses that provide good vision is very important.  In fact, many patients consider the refraction to be one of the most, if not the most important part of the eye exam.  When something seems wrong with the pair of glasses that results from the refraction, the patient can be very upset.

Glasses complaint evaluations should be scheduled as a regular appointment, because they almost always take as much time as, if not more time than, a yearly exam.  Tell the patient to bring in the old glasses also, if available.

Your attitude counts as much as any technical skills you may be bringing to the situation.  If fact, if your attitude stinks, your patient will be unhappy, no matter what you do.  Be concerned, be positive, and be apologetic.  When you take the patient into the exam room, the first thing you should do is sit down, look at your patient, and listen to what he has to say about the problem.  Most of the time the patient will give you valuable clues that will save you time in your evaluation.  Proceed with the evaluation as outlined below.  It does not matter much what order you go in, but it helps to tell the patient what you are doing and to keep them informed of the results.

No matter what the complaint is, there are a few evaluations that should be done for every glasses complaint, no matter how minor the complaint.  These should be checked because they take very little time, and they reveal common problems:

1) Confirm the prescription with the lensometer.

2) Mark the optical centers with the lensometer.

3) Measure the base curves with a lens clock.

4) Measure the patient's PD with a PD ruler.

5) Check the patient's distance and near vision with the glasses on.

6) Look at how the patient's glasses fit on his/her face.

Details:

1) Confirm the prescription with the lensometer.

This procedure, of course, will immediately reveal any gross errors in how the glasses were made.  You will want to read the old glasses as well if the patient is comparing the new ones to the old ones.  Do not rely on the information in the chart.  Just because someone wrote the Rx in the chart does not mean that it is accurate.  This is especially true of progressive lenses. 

2) Mark the optical centers with the lensometer.

This can be done quickly with the marking device of the lensometer, or with a Sharpie.  Many auto-lensometers do a fine job of finding the optical center.  Read the manual to your auto-lensometer and learn how to use the features.  Leave the marks on the glasses until the end of your evaluation.  Mark the optical centers of the old glasses if you are reading them.  Using a millimeter ruler, measure the distance between optical centers.  This is the "ocular center distance" or OCD.  For more information, see Module 17, Section 3.

3) Measure the base curves with a lens clock.

Be sure to measure the base curve of the old glasses also.  If the base curve of the new glasses is within one diopter of the base curve of the old glasses, and the prescriptions are not greatly different, you can assume that this is not a factor in the problem.  For more information see Module 17, Section 2.

4) Measure the patient's PD with a PD ruler.

The patient's PD measurement should be close to the OCD measurement.  If the difference is 3mm or less and if the spherical equivalent of the lens power is 2 D or less, you can assume the lenses to be within tolerance.  If not, and the patient has "pulling", "eyestrain", "headache", or "just not right" complaints, you will need to do a more extensive induced prism evaluation (Module 17, Section 3).

5) Check the patient's distance and near vision with the glasses on.

The patient's vision with the glasses on should match the vision of the previous refraction.  Pay attention to how the patient looks through the lenses. Does the patient look through the optical center?  Your small optical center dots should still be on the lenses.  Particularly with progressive lenses, the patient may need instruction on looking through the optical centers of the lenses. 

Pay attention to how the patient reads, particularly how far away the patient holds the reading material.  The patient may need instruction on holding the reading material at the focal distance of the bifocal.

6) Look at how the patient's glasses fit on his/her face.

With the head held level, does the patient look through the optical centers for distance vision?  Is the bifocal segment too high, or too low, for comfortable reading?  Is the vertex distance reasonable?  Are the patient's pupils close to the horizontal center of the lenses?  If not, the decentration may be adding unwanted thickness to the lenses.

Let the clues lead you

Once you become attuned to what to look for, this part of the evaluation will go very quickly.  Beyond these basics points of the evaluation, you will need to be led by the patient's complaints.  Some complaints have very specific and easy solutions, such as the patient who complains about poor vision from the left lens of the new glasses.  It may turn out that a sign on the prescription was transcribed wrong.  The evaluation will be more difficult for the patient who says the vision is good but the glasses "just don't feel right".  The next section will deal with specific problems.

Repeating the refraction

If the patient has a vision complaint, and there is not an obvious problem with the glasses matching the Rx, then you will need to repeat the refraction.  If you have gone through the evaluation process, and you have no clue as to what is causing the problem, you will need to re-check the refraction, even if the patient sees well.  If you don't, the patient will not think that everything possible has been done to evaluate the problem.  When refracting, refract carefully.  By being efficient you can do a careful refraction in a reasonable amount of time, without giving the patient the impression that she is being rushed.  If a significant difference is found, the glasses will need to be changed.

What if you can't find anything wrong with the glasses?

This does happen occasionally.  If you have shown concern to the patient about her problem, and she has seen that you have done a thorough evaluation, then most of the time the patient can accept that the glasses were made well from a good refraction.  Explain to the patient that she may acclimate to the glasses if given more time, and hope that this is the case.  Of course, the more experience you are at glasses evaluations, the more often you will be able to offer concrete solutions to glasses complaints.