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pippistrellodaqua, Optometrist
Category: Eye
Satisfied Customers: 134
Experience:  Specialty in contact lenses, medical eye management, LASIK
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I need an expert in RGP lens fitting. I saw an

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I need an expert in RGP lens fitting. I saw an opthalmologist today and was given diagnostic RGP lenses as I wanted to replace my old ones which are no longer comfortable. Old lens parameters are: Left/power -9.50/BC 7.94/diameter 9.2 & Right/power -9.0/BC 7.8/diameter 9.2. Optimum fitting diagnostic lenses are Left/power -3/BC 8.0 and Right/power -3/BC 7.9. Refraction data with diagnostic lenes on: Left/power -5.75/toric [email protected]° and Right/power -5.5. What are the optimal power parameters for ordering new lenses? Is it safe to order online as on

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Customer: replied 5 years ago.
Would like to have an answer.

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I have fit many RGP lenses in the past. I am out of the office tonight but have a tool that will assist me in giving you the correct information. I will post the answer in the morning when I can calculate the powers. The only risk in ordering the lenses online would be that often times as a doctor I make changes to the first pair of lenses after a diagnostic fitting. The diagnostic fit gives a great starting point but I frequently change the fit or the power slightly depending on the look of the new lens. If done in office most doctors will not charge for any changes made to the lens. I'm not sure how online lens companies will handle this.
Customer: replied 5 years ago.
It is really a nice thing that US doctors make slight changes to the lenses for fine tuning. In China doctor's standard is merely fitting OK. Power calculation is inacurate and never fine tuning. Charges for lenses are as high as 500 US dollars for a pair. This is why I want to order lenses on a US website by myself.
Thank you for your reply. Please take your time and post the answer when you are ready. It's been greatly helpful.
The lenses I would order based on the information you gave me would be:
Right eye: -8.62 DS, BC 8.0, diameter 9.2
Left eye: -8.12 DS, BC 7.9, diameter 9.2

Sometimes there is an extra charge for making a lens in 8th steps. If the up charge is too high you could consider using:
Right eye: -8.75 DS, BC 8.0, diameter 9.2
Left eye: -8.25 DS, BC 7.9, diameter 9.2

The extra power in the second set of lenses wouldn't likely be noticeable. Please let me know if you have any other questions. A positive rating would be much appreciated when your question has been answered fully.
Customer: replied 5 years ago.
Thank you for your answer. Why is power parameter of right eye higher than that for left eye? Did you mistake right eye for left eye?
No mistake on the lens powers. The right eye is a bit higher due to the astigmatism (toric) measurement reported in the right eye as well as the difference in the over-refraction power you had given. It was -5.75 and another -0.50 that I factored into the right eye and just -5.25 that was calculated for the left. Great question. There should be no problem in ordering lenses with two different powers based on the numbers you reported. Again, I usually make small changes once I see the lenses on the eye again, but this will be very close to perfect if not perfect.
pippistrellodaqua, Optometrist
Category: Eye
Satisfied Customers: 134
Experience: Specialty in contact lenses, medical eye management, LASIK
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