Term
What happens to the radius of curvature of a prolate cornea as you go from center to periphery? an oblate cornea? |
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Definition
A prolate cornea (normal) flattens as you go from the center of the cornea toward the periphery An oblate cornea (post lasik) actually steepens as you go from the center to the periphery
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Term
| Why would you use a back aspheric lens? A front ashperic lens? |
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Definition
1) back aspheric is for fit 2) front aspheric is for optics |
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Term
| Where should the edge apex be for an aspheric lens? |
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Definition
2/3 of the way toward the posterior of the lens, or just slightly posterior of the center. |
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Term
| What is the most used sphere lens in the clinic? |
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Definition
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Term
What is the main reason for a bitoric RGP? What are 4 accessory reasons? |
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Definition
1. better fit 2. RA, 3-9 staining, Spectacle blur, flexure |
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Term
What do you call a fit that is on K in each meridian? |
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Definition
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Term
| For which type of toric contact lens must you specify an axis when ordering? Which ones do you not specify an axis? |
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Definition
1. front toric 2. back toric or bitoric |
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