Eye Matters
November 9, 2010
Is my prescription correct?

Dear Dr. Onu,

I would like you to explain this situation to me. Recently, I went to see an eye specialist and was told that I suffer from hyperopia, astigmatism and presbyopia.{{more}}

They proceeded to give me a prescription and dispensed glasses. When I received the glasses I found that I could not focus very well in the distance with them. As a matter of fact, while wearing them I felt a pressure above my eye brows and by the end of the day I had a bit of a headache.

I revisited the eye specialist only to be told that I needed time to get used to the new glasses. They rechecked the prescription and confirmed that the prescription was correct for my eye sight.

It has now been three weeks and I still feel that something is wrong with this prescription.Is it possible that that they are not telling me the truth? I still feel the pressure around my eyes, and I am of the opinion that the prescription may be too strong. Please explain!

Signed by Worried…….

Dear Worried,

Your situation is not unique. I know you must be quite concerned about your prescription not being correct. If you have hyperopia, astigmatism and presbyopia it means that you are far sighted, have an irregular eye shape and that you have reached the age for reading glasses. I would like to reassure you, however, that these things are possible. My advice would be to first have your eye practitioner recheck not only the prescription but also the alignment of the eye glass on your face, as this may also cause problems.

Other things to look out for are:

1. That the interpupillary distance is correct (this is the distance between the centre of both eyes). It is important for eye glasses to fit properly.

2. Check the optical material and make sure that the lenses are centered and not warped in any way.

3. Sometimes even though the prescription is correct you could be suffering from excessive overfocusing and that could be a cause of the headaches.

This is what we call an accommodative error. I have seen many cases when the prescription was correct, but where the eye care practitioner had to reduce the power in order for the patient to feel comfortable.

4. Make sure that you do not suffer from any eye diseases, such as diabetes, that could cause a temporary shift in your prescription.

Usually when such cases occur we recommend that the pupils be dilated so as to block the focusing muscles of the eye. This process makes prescribing much easier ( cycloplegic refraction) albeit it causes the vision to be blurry for awhile.

Of course there are many other reasons why you may be having problems. Even though there is nothing wrong with a second opinion it is always best to return to the person who prescribed the glasses in the first place so they can rule out all other possibilities.

Next week I will discuss in more detail all the other things that could lead to the prescription being correct but the patient not seeing properly.

Dr Kenneth Onu is a resident Consultant Ophthalmologist at the Beachmont Eye Institute/Eyes R Us Send questions to: Beachmont@gmail.com

Tel: 784 456-1210