Kate wrote:
Hello,
I went to an optometrist yesterday. He was not very talkative; I was asking a lot of questions as he was doing exams and just writing stuff down. He would answer me with one word answers. Then, without explaining why, he put drops in my eyes, I didn’t even have time to ask “why”. Only after he had already put them in he said it was to measure pressure. Also, I know from previous exams that I have astigmatism. To him, however, this was irrelevant as it is not in my prescription! He said my problem was focusing of the eyes, on my prescription there is a number 6 in column “prisme” and it looks like it’s a fraction, but I cannot read it. Should I get another exam? If I bring my prescription from 2 years ago and this one (as my eye sight did not change at all), will I be able to get lenses?

ANSWER

Kate,
I would recommend calling your optometrist’s office.  Optometric assistants are very knowledgeable and would be able to answer your questions about your prescription.  Astigmatism can change throughout your life and it is possible it may have improved.  You will be able to get new glasses with your new prescription.

Dr. Doman

Timmy wrote:
Hi, i have a question regarding prescriptions for glasses and contacts. I understand you should not be using the degrees prescribed to you for glasses for buying contacts because contact lenses sits on your eyes directly as opposed to the glasses being a few inches away.
So my question is, would my eyes get worst or some sort of negative impact if I do wear contact lenses having the same degrees as my eye glasses?
the degrees for contacts should be slightly stronger or weaker? so if you wear contact lenses that are not exactly the same degree, what are the dangers of doing so? will it be merely less clear or will it make your eye sight worsen?

Thank you for your time

ANSWER

Hello Timmy,
Yes it is true that in most cases the prescription your optometrist gives you for your glasses is different than the one given for your contact  lenses.  Whether the contact lenses are stronger or weaker will depend on the prescription.  Wearing contact lenses that are the incorrect prescription (stronger or weaker) can cause symptoms of blur, headaches, dry, uncomfortable eyes and/or spasm of your focusing system.  Furthermore, if the lenses do not fit correctly, there are many other eye-health related problems that you would be at risk for.
When purchasing contact lenses from your optometrist, he/she will ensure that you have the correct strength and fit needed, and would be happy to give you a copy of that prescription for your records.

Thank you for your question. 
Dr. Donati

Dominique wrote:
How important is the precision of  the “axe” values in the prescription? These values change each time I go to a different optometrist and the latter do not all provide the same precision for their measurements. Specifically, 7 years ago I got the values R/L 175/170, 1 year ago, 165/178 and this year 170/180. I would like to purchase bi-aspherical lenses, but those are expensive, so I would like to be sure that my prescription is good enough.

ANSWER

Dominique,

The axis value (or axe in French) is an important part of a glasses prescription.  However, this value can vary from visit to visit.  The axis represents the orientation of the power of your astigmatism.  The power of your astigmatism is the second number on your glasses prescription.  If you have a small amount of astigmatism (I would say less than -1.50), it is possible for the axis to vary from visit to visit sometimes by approximately 10-20 degrees.  On the other hand if you have a large amount of astigmatism, this number would likely only vary within 5 degrees.  From looking at your numbers, especially from last year to this year the change in axis is very small.  When you purchase new lenses if you have any problems all optometrists and opticians will work with you to solve the problem.  I would go ahead and get the new prescription filled.

Dr. Carol Doman

Amira wrote:
Hi. It’s been 4 years since I’ve had an eye exam. Recently I got one and my RX was -5.25. My contacts prior to this were -3.25. I purchased my glasses with the new RX and it’s been 2 weeks since I’ve been wearing them but they sometimes make me feel off balance and they appear TOO clear and my eyes feel a bit of strain. Does this mean my RX is too high or should I give myself more time to adjust to wearing the glasses?

ANSWER

Dear Amira:
It is certainly possible for your eyes to change as much as you have noted over a period of four years, especially if you are under twenty years of age. Such a large change in prescription often creates difficulty in adaptation for a few weeks. If after four weeks your symptoms are not showing signs of improvement, I would bring your concerns to the attention of your optometrist.
Best regards,
Dr. Henry Smit

Jayne wrote:
The Dr. that refracted my son’s eyes wrote his prescription as:

Right Eye: +100 +200 x 110
Left Eye: 150 +225 x 75

But the store that made his glasses interpreted this as:

Right Eye: +3.00 -2.0 x 20
Left Eye: +3.75  -2.25 x 165

Is this correct? He has astigmatism and needs glasses for distance.

ANSWER

Hello Jayne,
Yes these two prescriptions you have given me are exactly the same.  This is just a different way of recording the information.
Thanks for your question,
Dr. Donati

Jo wrote:
Hello

I was at the optometrist 1 month ago, and they give me a sample pair of regular contact lenses of both -6.50 which are to be worn night and day for a period of 1 month.
I have astigmatism and got the original lenses 1 week ago, Bausch and Lomb Purevision toric night and day.
My ophthalmologist prescription was:
RE: -7/ -1.5 axis: 15
LE: -7.25/ -1.75 axis: 170

On the optometrist prescription was following:
RE: -6.50 /-1.75 axis 10
LE: -6.50 /-1.75 axis 170

The axis for the LE went 5 less, I don’t understand why.

Both are 8.7 radius and diameter of 14.00.
I feel there is a blur sometimes on the nasal corner of both eyes which comes and goes with time and the vision feels blurry. I checked the lenses and there is something written on them with a small mark. Is there a particular way to put them in? The optician didn’t say anything about this.

When I order my next pairs of contact lenses could I maybe order the axis of 15 instead of 10 for the RE?
Thank you in Advance.

ANSWER

Dear Jo

The prescription for spectacles and contact lenses is often a bit different as contact lenses sit on the cornea (front of the eye) - depending on how the lenses fit, thus causes changes both to the power and axis of the astigmatism.  You will always see better with your spectacles rather than contact lenses as lenses need to move for good tear exchange. So, every time you blink you will have a loss of focus for a second or two.  There are marks on the contact lenses to check how they sit and fit to your eye.  Due to gravity and the built in prism ballast, the marks usually point downwards.  If you can orientate the marks to point down before you put the contact lenses in it will settle faster.  If you are having problems with the contacts it is a good idea to have a contact lens check before you order new ones.

Serdar wrote:
Hi,
I have a question regarding legality. This is my first time I’m buying contact lenses. My opto told me that I need a training period. I did this 2 months ago and I paid $55 for this training since my lenses are customized toric. Then I had to go out of town for about 1.5 months. When I came back and I asked the price of lenses for 6 boxes, they told me a higher number. So, I asked them for my lens prescription in order to get advice from another opto but they didn’t give me my lens prescription. I only have my eyeglasses prescription, which I know little bit different than contact lens prescription. Are they allowed not to give me my prescription? Do I have to buy from that optometrist?
Thanks

ANSWER

Hi Serdar,
Customized toric lenses are a specialized product and do cost more than regular disposable contact lenses.  Generally if the contact lens fitting is completed then the prescription for contact lenses can be released.  However if the fitting was not completed then the contact lens prescription is not released as there is no final prescription.  To have the fitting complete all of the follow up visits must be attended to and the contact lens fit and vision through them need to be satisfactory to the optometrist.  If all of these things were not completed the fit is not finalized.  If you are going to visit another optometrist they are likely going to do a new fitting on you, as they will want to ensure that everything is satisfactory with the contact lenses before you purchase them.  You would just need your glasses prescription in that case.
Dr. Doman

Lucia wrote:
Hello,
Regarding prescriptions, do I have the right to ask for my PD when I have my eyes examined by a licensed optometrist? I would like to have to option to shop around when I get new glasses, and since I am paying for a service (the eye exam), I would like to have a complete prescription written out. What resources do I have if I am denied the PD value for my prescription?

Thank you.

ANSWER

For regular glasses, a PD is not part of the prescription.  The person who makes your glasses needs to check that themselves and they have special instruments to do that.

Dr. Joan Hansen, Optometrist for CAO

Marla wrote:
Is it true that an optometrist and ophthalmologist use a different system to measure or determine the prescription needed for glasses.  I was told that a prescription from an ophthalmologist must be “converted” to optometrists’ measurement and that I may still require seeing an optometrist for another test of my eyes to get new glasses.

Please advise, thanks,
Marla

ANSWER

Marla,
It is true that optometrists and ophthalmologists use different ways of recording a glasses prescription.  Optometrists use what is known as ‘minus cylinder form’ and ophthalmologists use what is known as ‘plus cylinder form’.  They are both measuring the same thing, but are just recorded in a different format.  If you have a valid prescription from an ophthalmologist you would not need to see an optometrist for any additional tests before getting glasses.
Dr. Doman

Mark wrote:
Hi,
I began wearing glasses about 10 years ago for myopia as a child.  About 5 years ago, I dropped my glasses entirely, and instead began using contact lenses (at which point my prescription had not yet stabilized).  I currently use a prescription of -4 in each eye with contact lenses.  I recently purchased glasses for the first time in a while, using the -4 prescription given by my optometrist and immediately noticed a marked drop in visual acuity compared to that with my contact lenses.  Do I have to visit my optometrist (who was not aware of my purchase of glasses) to get a different prescription for glasses, or is a usual occurrence with glasses/contact lenses?

ANSWER

Mark,

If it has been more than one year since you saw your Optometrist to get that -4.00 prescription, I would suggest a new exam to make sure that the prescription is still adequate.  It is also true that vision often is better with contact lenses than with glasses, even if the prescription is completely up to date.  The contact lenses sit right on the surface of the eye, and allow the images to remain very close to normal size.  Glasses sit farther away from the eye and minimize (make smaller) the image which makes it seem more out of focus.   I’d still recommend and exam just to be sure.

Dr. Joan Hansen, Optometrist for CAO