100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
NCLE Basic Exam Study Guide QUESTIONS AND CORRECT DETAILED ANSWERS |ALREADY GRADED A+ $12.99   Add to cart

Exam (elaborations)

NCLE Basic Exam Study Guide QUESTIONS AND CORRECT DETAILED ANSWERS |ALREADY GRADED A+

 3 views  0 purchase
  • Course
  • NCLE
  • Institution
  • NCLE

NCLE Basic Exam Study Guide QUESTIONS AND CORRECT DETAILED ANSWERS |ALREADY GRADED A+

Preview 2 out of 7  pages

  • November 1, 2024
  • 7
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers
  • ncle
  • NCLE
  • NCLE
avatar-seller
Ashley96
NCLE Basic Exam Study Guide

1. "K" is the ____ of the two meridians - ANS-flatter
2. 4 refractive mediums - ANS--Cornea
3. -Aqueous
4. -Crystalline Lens
5. -Vitreous
6. A ____ fitting lens is fitted flatter than K and will touch at the corneal apex with excessive
movement over the cornea. It is not uncommon for this lens to fall off the eye or become
easily decentered. Such a lens may cause abrasions at the corneal apex and may also
cause corneal edema. - ANS-loose
7. A lens with a steep CPC that vaults the corneal apex and touches the cornea at its
peripheries is considered a ____ fittinglens. This lens will not ride freely over the cornea
and will generally cause corneal edema and subsequent spectical blur. - ANS-tight
8. Back Surface Toric Lens - ANS--A contact lens that has two different and perpendicular
radii of curvature on its posterior surface only
9. -Has a spherical anterior surface
10. -Only functional when manifest cylinder is 1.5 times greater than corneal astigmatism
11. -Only used when the corneal toricity is so great that alignment in all meridians is not
possible
12. -Toric curves on the posterior surface are required when a spherical lens results in areas
of excessive clearance or bearing
13.
14. example: -2.00-4.00x180
15. 42.00@180/45.00@90
16.
17. Refractive Cyl: 4.00D
18. Corneal Cyl: 3.00D
19. Bitoric Lens - ANS-A contact lens that has two different and perpendicular radii of
curvatures on both the anterior and the posterior surfaces
20. Central Anterior Curves (CAC) - ANS--Radius of curvature of the anterior portion of the
lens
21. -Determines power of the finished lens
22. -Varies from lens to lens
23. -Must compute with the CPC to yield the pre-determined power
24. -Not relative to the fitting of the lens, only to its manufacture
25. -Does not have to relate to the surface power of the cornea
26. -Expressed in mm of radius of curvature
27. -Manufacturers have slide rules/charts available to relate the CAC to a required power
from a given CPC and thickness

, 28. Central Posterior Curve (CPC) - ANS--The Posterior radius of curvature designed to
conform to the apical zone of the cornea
29. -Must be highly polished and of definite optical quality
30. -Referred to in terms of the surface power of the cornea to which it is related
31. -Should be expressed in diopters, followed with its radius in mm enclosed in parenthesis.
32. -AKA base curve or radius
33. Complex formula for vertex distance - ANS-Fᴮ = ____Fᴬ____ *WVtx is less than RVtx
34. 1-(dFᴬ)
35.
36. Fᴮ = ____Fᴬ____ *WVtx is greater than RVtx
37. 1+(dFᴬ)
38.
39. Fᴬ = primary focal length of the RVtx
40. Fᴮ = focal length of the compensated power at the WVtx (eyewear or CL)
41. d = distance in meters that the lens has been moved
42.
43. *always round answer to the nearest 0.125D
44. Corneal Topography - Axial Map - ANS--Most widely understood map of the cornea for
many CL fitters
45. -Overall shape of the cornea
46. -Colors relate to steepness/flatness
47. -Sagittal reading measures the curvature of the cornea in diopters and is called the axial
power map
48. -Calculates curvature rather than power
49. Corneal Topography - Elevation Map - ANS--Shows the difference in the elevation of the
cornea
50. -Measured in microns
51. Corneal Topography - Irregularity Map - ANS--Similar to elevation maps
52. -Uses best fit toric surface as a reference
53. -Eliminates any toricity from the eye and displays the elevation differences
54. Corneal Topography - Keratometry Views - ANS--Represent the keratometric readings
along with the axes of the eye's presumed astigmatism
55. -Dioptric values define the findings from the center of the cornea to the periphery
56. -This view helps the practitioner to quickly determine if corneal astigmatism is
symmetrical
57. Corneal Topography - Numerical Views - ANS--Arranges individual keratometric findings
to depict curvature readings of the eye
58. -Extremely useful when fitting specialty contacts
59. -Corneal topographic software calculates the "average keratometric" value
60. Corneal Topography - Photokeratoscopic Views - ANS-Uses the placido rings which are
reflected onto the eye to subjectively determine the location and regularity of the rings
61. Corneal Topography - Profile Views - ANS--Graphically represent the individual axes of
the cornea to help depict the 3-D nature of the cornea
62. Corneal Topography - Refractive Power Map - ANS--Show spherical aberrations

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller Ashley96. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $12.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

84146 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$12.99
  • (0)
  Add to cart