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Dr. Rick
Dr. Rick, Board Certified MD
Category: Eye
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Experience:  Ophthalmology since 1994 with Retina sub-specialty interest
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Hi, this question is regarding contact lenses. My prescription

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Hi, this question is regarding contact lenses.

My prescription (for glasses) is
L -6.25 -0.75 x 12
R -5.25 -0.75 x 170

First of all, can you explain what these number refer to? And what contact prescription should I get, and how does astigmatism translate to in contact lenses?

My current optometrist asked me to try on contact lenses of L -6.00 BC 8.5 Dia 14.2, R -5.25 BC 8.5 Dia 14.2, but I feel weird and not able to focus well with them. So I'm wondering whether they're the wrong prescription.

Thanks

Dr. Rick :

Hi. My name isXXXXX and I have two decades of ophthalmology experience. I'm online and happy to answer your question today.

Dr. Rick :

Let me go over your Rx in order: L -6.25 -0.75 x 12


 


This is for your left eye. -6.25 is the "sphere" component of your refraction. You are fairly nearsighted.


 


the -0.75 is the astigmatism part. It oriented at axis 12. This is not very much astigmatism as things go....

Dr. Rick :

This is for your right eye: R -5.25 -0.75 x 170.


 


Once again the -5.25 is the sphere and the -0.75 is the cylinder (astigmatism) part, oriented this time at axis 170. This is about the same as your left eye.....

Dr. Rick :

Contacts lenses can not be directly prescribed from this data for making glasses as the lenses have to be fit to the size and curve of your cornea (the front part of your eyeball).

Dr. Rick :

That being said, contact lenses would not have have the cylinder (astigmatism) ground into them like your glasses do since, due to a lot of physics and optics which is kinda beyond the scope of this discussion, the contact lens makes a "tear film lens" that "takes care of " the small amount of astigmatism you have....

Dr. Rick :

It is impossible to tell if your contact lens Rx is incorrect from the data you have provided. If you've not had the lens for at least three weeks of full time wear, give them time as it may take some time for eyes to adjust to the contacts.

Dr. Rick :

As far as the Rx (power) of the contacts go the numbers you listed are consistent with your glasses Rx.

Dr. Rick :

So. What is the take home message? Give the lenses time. If you are still having problems with near vision perhaps the lenses are too "strong" ( too much minus power) and you might benefit from a wet/dry refraction to uncover this problem....or maybe the lenses are a poor fit....in any event your optometrist should be able to figure it out.

Dr. Rick :

Is there anything else you would like to discuss at this point or have all your questions been answered to your satisfaction?



I hope this information was helpful for you. But I do work for tips so I want to make sure you are happy with me before rating me. If you have another question on this or a related issue feel free to fire away. You may also receive an email survey after our chat, if you don’t feel that I have earned a “10” rating in all areas, please let me know what I can do to meet your expectations.

Thanks in advance,

Dr. Rick MD FACS

Dr. Rick :

I see that you are offline. I will switch to Q&A format. This format works a lot like 'text messaging' but an email is sent to each of us anytime something is posted to this thread. We can continue to work on your question there..... :)


Dr. Rick : Hi. My name isXXXXX and I have two decades of ophthalmology experience. I'm online and happy to answer your question today.
Dr. Rick : Let me go over your Rx in order: L -6.25 -0.75 x 12

This is for your left eye. -6.25 is the "sphere" component of your refraction. You are fairly nearsighted.

the -0.75 is the astigmatism part. It oriented at axis 12. This is not very much astigmatism as things go....
Dr. Rick : This is for your right eye: R -5.25 -0.75 x 170.

Once again the -5.25 is the sphere and the -0.75 is the cylinder (astigmatism) part, oriented this time at axis 170. This is about the same as your left eye.....
Dr. Rick : Contacts lenses can not be directly prescribed from this data for making glasses as the lenses have to be fit to the size and curve of your cornea (the front part of your eyeball).
Dr. Rick : That being said, contact lenses would not have have the cylinder (astigmatism) ground into them like your glasses do since, due to a lot of physics and optics which is kinda beyond the scope of this discussion, the contact lens makes a "tear film lens" that "takes care of " the small amount of astigmatism you have....
Dr. Rick : It is impossible to tell if your contact lens Rx is incorrect from the data you have provided. If you've not had the lens for at least three weeks of full time wear, give them time as it may take some time for eyes to adjust to the contacts.
Dr. Rick : As far as the Rx (power) of the contacts go the numbers you listed are consistent with your glasses Rx.
Dr. Rick : So. What is the take home message? Give the lenses time. If you are still having problems with near vision perhaps the lenses are too "strong" ( too much minus power) and you might benefit from a wet/dry refraction to uncover this problem....or maybe the lenses are a poor fit....in any event your optometrist should be able to figure it out.
Dr. Rick : Is there anything else you would like to discuss at this point or have all your questions been answered to your satisfaction?

I hope this information was helpful for you. But I do work for tips so I want to make sure you are happy with me before rating me. If you have another question on this or a related issue feel free to fire away. You may also receive an email survey after our chat, if you don’t feel that I have earned a “10” rating in all areas, please let me know what I can do to meet your expectations.

Thanks in advance,

Dr. Rick MD FACS
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